RAD-140
Not medical advice. PepTutor summarizes fallible research and community signal for trained practitioners; some compounds are research-only, unapproved, controlled, jurisdiction-dependent, or labeled not for human consumption.
RAD-140 is a high-potency oral SARM for dry strength, lean-mass gain, muscle retention during cuts, and recomposition; it belongs in the advanced androgenic-cycle lane, not the mild-supplement lane.
RAD-140 has real suppression and liver-risk baggage: testosterone can crash, cholestatic hepatitis is documented in humans, and any cycle needs bloodwork plus an off-ramp plan before the first dose.
RAD-140 is a high-potency oral SARM for dry strength, lean-mass gain, muscle retention during cuts, and recomposition; it belongs in the advanced androgenic-cycle lane, not the mild-supplement lane.
Testosterone suppression (potentially permanent without recovery), drug-induced liver injury (cholestatic hepatitis documented in humans), androgenic alopecia acceleration, aggression/mood dysregulation, no long-term safety data at recreational doses
One of the most potent oral SARMs available: the upside is visible strength/recomp at 10–20mg/day; the price is a full suppression, liver-marker, lipid, source-quality, and off-ramp burden
High for strength and lean mass in community use; intermediate lifters commonly report 10–25% strength increases and 5–10 lbs lean mass over 8 weeks at 15–20mg/day, but these are uncontrolled logs rather than clinical body-composition trials
Do not treat RAD-140 as a casual solo oral. Without a testosterone base, concurrent HPG support, or a real PCT/off-ramp plan, suppression can turn the second half of the cycle into low-testosterone symptoms plus harder recovery
Intro
RAD-140, or Testolone, is a non-steroidal selective androgen receptor modulator (SARM) developed by Radius Health in 2010 (Miller et al., ACS Medicinal Chemistry Letters).
Its original purpose was treating muscle wasting and hormone receptor-positive breast cancer — not physique enhancement. The foundational characterization paper described a potent AR agonist (Ki = 7 nM, vs testosterone's 29 nM) with tissue-selective anabolic effects in muscle and bone and relative sparing of prostate and seminal vesicles. This selectivity profile, combined with oral bioavailability and a clean preclinical safety signal, made it a target for both oncology applications and self-managed fitness communities.
The fitness community first encountered RAD-140 around 2015, when early cycle logs appeared in bodybuilding communities. By 2016–2017, it was being discussed alongside LGD-4033 as one of the more potent SARMs, and by 2020 it had become one of the top-3 most-discussed SARMs globally. The primary drivers of adoption: oral administration, lean/dry gains without water retention, and stronger strength gains than Ostarine at equivalent effort. Community educators positioned it as 'the Anavar of SARMs' — a compound delivering defined, strength-focused gains without the water-bloated look associated with LGD-4033.
On the clinical side, RAD-140 has progressed further than most SARMs. A Phase 1 dose-escalation trial in ER+/HER2- metastatic breast cancer patients (LoRusso et al., 2022, Clinical Breast Cancer) established preliminary safety and antitumor activity. Doses tested in that trial — 50 to 150 mg/day in cancer patients — are 3 to 15 times the recreational dose range. A separate Phase 1 abstract from the AACR (Hamilton et al., 2020) identified dose-limiting toxicities primarily as liver function test elevations at higher dose cohorts. The 2022 German Sports University doping control study (Wagener et al.) measured human pharmacokinetics and confirmed a ~60-hour elimination half-life.
Critically, all human muscle-building data remains anecdotal — no controlled trial has evaluated RAD-140 for body composition endpoints at the 10–20 mg/day doses used recreationally. The entire community-level evidence base is uncontrolled individual experimentation. This is the honest framing: a compound with a plausible mechanism, solid preclinical data, early-stage human safety signals from cancer trials, and several years of community-level use that has documented both genuine efficacy and real safety events including hepatotoxicity.
Observed Effects
In self-managed fitness communities, RAD-140 at 10–20 mg/day over 8 weeks produces consistent reported outcomes: strength increases of 10–25% in major compound lifts (bench, squat, overhead press) for intermediate lifters; lean body weight gain of 5–10 lbs at caloric maintenance; and meaningful recomposition — simultaneous fat loss and muscle gain — when calories are controlled near maintenance.
Strength gains tend to appear earliest, typically within 2–3 weeks of starting. Muscle fullness (increased glycogen and protein synthesis in muscle cells) is often noticed within the first week at higher doses. The most reliable community reports describe a 'sweet spot' from weeks 3 through 6, when strength and recovery peak without the suppression becoming problematic.
Anecdotal high-response reports include unusually large weight gain in underweight or beginner-adjacent users, but these are not representative of experienced-lifter outcomes and can confound drug response with training, diet, and baseline recovery. More typical community logs emphasize strength PRs and lean/dry scale movement rather than guaranteed mass gain.
Preclinically, RAD-140 increased muscle fiber cross-sectional area in unstimulated limbs (Puskas et al. 2025, Sprague-Dawley rats, 14 days), confirming the androgen-mediated hypertrophy mechanism independent of mechanical loading. In orchidectomized Wistar rats (Budaya et al. 2025, 6 weeks), RAD-140 significantly increased osteoblast count, myonuclei number, and muscle fiber CSA while decreasing osteoclasts — the anti-catabolic bone-muscle dual effect that makes it relevant for androgen-deprived states.
Neuroprotective effects are reported in animal models — RAD-140 crosses the blood-brain barrier and activates brain AR, potentially protecting neurons in androgen-deficient conditions. This is a mechanistic finding without clinical translation to date.
RAD-140 does not aromatize, meaning no estrogenic effects — no water retention, no estrogen-mediated gynecomastia, and no estrogen-driven fat redistribution. The absence of aromatization is both a benefit (lean gains) and a limitation (no estrogen-mediated bone protection, reduced libido support over extended cycles).
Field Reports
The most consistently reported RAD-140 experience pattern across cycle logs, forum threads, and first-person reviews over 10 years:
Weeks 1–2 (adjustment): First-week lethargy is common — users report needing 8–12 hours of sleep, reduced energy in training sessions, and mild general fatigue. This appears to be a transition effect rather than a persistent side effect, as it resolves for most users by the end of week 2. Some users report early libido increase from the initial androgenic stimulation. Acne in susceptible users begins around days 7–14.
Weeks 3–6 (peak performance window): Strength gains become pronounced and consistent. Compound lift PRs are commonly reported — bench press, squat, deadlift, and overhead press all respond. Muscle fullness is visible. Recovery between sessions improves. Users describe a sense of 'anabolic' momentum — sessions feel productive and progressive consistently. Energy levels have recovered from the week-1 dip. This is the phase that drives positive reviews and repeat cycles.
Weeks 7–8 (diminishing returns): Most users notice that the rate of strength gain slows. The experienced practitioner community's 8-week recommendation reflects this plateau pattern. For users running solo (without testosterone base), mild libido decline may begin emerging as suppression deepens.
Common mistakes identified across the community: 1. Running RAD-140 solo without testosterone base or concurrent Enclomiphene/HCG and then being surprised by mid-cycle libido crash and post-cycle suppression 2. Eating in large caloric surplus with high carbohydrates and attributing all weight gain to muscle — the recomp effect requires dietary discipline 3. Skipping bloodwork — not knowing baseline LFTs means no ability to identify hepatotoxicity developing 4. Expecting LGD-4033-style mass gains — RAD-140 builds lean mass differently; expecting bloat or scale weight equivalent to LGD is a set-up for disappointment 5. Running 12-week cycles without data supporting safety beyond 8 weeks — diminishing returns combine with accumulating suppression and hepatic load
Protocol evolution: Early community (2015–2017) ran RAD-140 more aggressively and without concurrent hormonal support. Current experienced community strongly recommends testosterone base or concurrent Enclomiphene/HCG. PCT guidance has evolved away from Nolvadex/Clomid toward Enclomiphene as primary. The hepatotoxicity awareness has increased following published case reports — LFT monitoring is now standard advice in informed communities where it was rarely discussed in 2015.
What experienced users report working: 15–20 mg/day on a testosterone base, 8-week cycle, calories near maintenance for recomp or modest surplus for lean bulk, bloodwork before and mid-cycle, injectable glutathione for liver support, topical Minoxidil/RU-58841 if any hairline concern. This is the community's current best-practice stack.
Community Consensus
RAD-140 is one of the most discussed SARMs in English-language bodybuilding and fitness communities. Discussion volume has been sustained since the mid-2010s despite the maturation of the SARM market.
The compound's reputation splits along experience lines. Younger and beginner-adjacent users are attracted by oral administration and dramatic anecdotal scale-weight reports, while experienced compound users more often frame RAD-140 as an addition to a testosterone base rather than a standalone protocol. TRT-focused discussions tend to be more cautious, with more emphasis on bloodwork, long-term unknowns, and the limits of solo SARM use.
A distinctive RAD-140 community characteristic is the aggression discussion: more users raise aggression and mood intensity as notable effects compared with LGD-4033 or Ostarine. Gym-focused users may interpret that as training intensity; health-focused users tend to treat it as a social and impulse-control cost.
The compound's "Anavar of SARMs" nickname emphasizes lean, dry, strength-focused gains without water retention. When users compare RAD-140 with LGD-4033, the stable shorthand is RAD for dry aesthetics and strength, LGD for maximum scale weight and fullness.
Risks & Monitoring
Testosterone suppression (common, dose-dependent, potentially severe): RAD-140 suppresses the hypothalamic-pituitary-gonadal axis via negative feedback, reducing LH, FSH, and consequently endogenous testosterone.
Some community educators warn that incomplete recovery and eventual TRT dependence are real risks after repeated or poorly managed SARM use. The degree of suppression is dose- and duration-dependent — heavier doses and longer cycles increase the risk of incomplete recovery. Users running RAD-140 solo (without testosterone base or concurrent Enclomiphene/HCG) typically experience a libido crash by mid-cycle as endogenous testosterone is suppressed without replacement.
Hepatotoxicity (uncommon but documented): A published case report (Leung et al. 2022, Ochsner Journal) documented RAD-140 drug-induced liver injury with cholestatic hepatitis pattern — jaundice, elevated LFTs, and liver biopsy confirmation. LFTs normalized after discontinuation. Additional case reports have documented bilirubin peaks up to 38.5 mg/dL in severe DILI cases. The clinical Phase 1 trial also identified LFT elevations as dose-limiting toxicities at 50–150 mg/day. While recreational doses are lower, the mechanism is active and the risk is not zero. Rapid weight gain on high-carbohydrate diets during RAD-140 use may compound liver stress.
Androgenic alopecia acceleration (risk for susceptible individuals): RAD-140 does not convert to DHT via 5-alpha-reductase (non-steroidal scaffold cannot be processed this way), but it still activates androgen receptors directly in hair follicles. Users with androgenic alopecia genetics consistently report accelerated hair loss. Users without genetic predisposition report minimal shedding. Finasteride is not an effective mitigation strategy since the mechanism is direct AR agonism, not DHT. Topical RU-58841 and/or topical Minoxidil 10% are the community harm-reduction options.
Aggression and mood dysregulation (common, dose-dependent): RAD-140 produces stronger androgenic CNS effects than LGD-4033 or Ostarine at comparable doses. Elevated aggression, irritability, lower impulse control, and an 'alpha feeling' are commonly reported — particularly during weeks 2–6. This CNS effect is consistent with AR agonism in brain tissue. Some users view it as a training advantage; others report social difficulties.
First-week lethargy (common, transient): Many users report 8–12 hour sleep requirements and general fatigue during the first 1–2 weeks of a cycle. This typically resolves as the compound reaches stable state. Mechanism unclear — possibly related to the transition in androgen balance.
Acne (moderate risk, dose-dependent): Sebaceous gland AR activation drives acne in susceptible users. Onset typically around days 7–14. More common in users with oily/acne-prone skin baseline.
Cardiovascular (rare, mechanism unclear): A case report has documented acute myocarditis (troponin 100.5 ng/mL, left ventricular ejection fraction 15%) in a 22-year-old SARM user. The mechanism is unclear and contaminated underground products cannot be ruled out as a contributor. The FDA explicitly warns that SARMs may increase risk of heart attack and stroke.
What's absent or uncommon: No estrogenic side effects (no aromatization). No prostate stimulation confirmed in animal studies (RAD-140 is a partial antagonist at prostate AR). No significant water retention — the dry gains profile is consistent and reliable.
For Women
Monitoring Panels
REQUIRED is a real safety gate. RECOMMENDED is the prudent default. OPTIONAL covers symptoms, risk factors, or tighter tracking.
Establishes pre-cycle hormonal baseline. RAD-140 suppresses HPG axis — without a baseline, you cannot measure the degree of suppression during or after a cycle or confirm recovery. Essential for PCT decisions.
Baseline RBC, hemoglobin, hematocrit, and platelets. Androgens stimulate erythropoiesis — RAD-140 can elevate RBC and hematocrit (polycythemia risk). Baseline establishes the starting point for comparison.
RAD-140 drug-induced liver injury is documented in humans. LFT baseline is mandatory — ALT and AST elevations during cycle are the early warning signal for hepatotoxicity. Bilirubin is the severity marker in cholestatic injury.
Androgens typically suppress HDL and may elevate LDL. RAD-140 has the same mechanism. Baseline lipid profile needed to detect adverse cardiovascular lipid shifts during cycle.
Given documented DILI risk with RAD-140, mid-cycle LFT check (around week 4) provides an early warning window. Elevations >3x ULN (upper limit of normal) are the standard threshold for discontinuation. This is the most important mid-cycle safety check.
Measures the degree of HPG axis suppression at mid-cycle. Informs whether concurrent Enclomiphene or HCG dose needs adjustment. Also identifies outlier non-suppressors or hyper-suppressors.
Hematocrit monitoring for polycythemia. More relevant for longer cycles (10+ weeks) or users stacking with other androgens.
Confirms HPG axis recovery after PCT. Primary decision point: if testosterone and LH/FSH are not recovering toward baseline at 4–6 weeks post-cycle, TRT consultation is warranted. This is the most important post-cycle panel.
Confirms liver enzyme normalization after discontinuation. Published DILI cases resolved with LFT normalization after stopping RAD-140 — this panel confirms the pattern.
Confirms HDL recovery and lipid normalization. HDL suppression by androgens typically reverses within 4–8 weeks of discontinuation.
Avoid With
Do not combine RAD-140 with the following. Sorted highest-severity first.
Why:Both RAD-140 and alcohol are hepatotoxic — concurrent use significantly elevates DILI risk. Given documented RAD-140 liver injury cases, adding alcohol removes the safety margin entirely.
What to do:Avoid alcohol for the duration of any RAD-140 cycle. This is not negotiable from a liver safety standpoint.
Why:All oral 17-aa steroids are hepatotoxic via the same pathway as oral anabolics. Stacking with RAD-140 (which has its own DILI risk) multiplies hepatotoxicity burden and can produce acute liver failure.
What to do:Do not stack RAD-140 with oral 17-aa AAS under any circumstances. Injectables are safer but still add androgenic burden.
Why:Stacking multiple SARMs significantly increases suppression depth and duration. Double or triple SARM stacks can produce suppression equivalent to or exceeding anabolic steroid cycles, with more uncertain recovery patterns. Hepatotoxicity risk may also be additive.
What to do:If stacking SARMs (e.g., RAD-140 + LGD-4033), a testosterone base becomes more strongly indicated. Blood work monitoring frequency should increase. Cycle length should decrease.
Why:Running RAD-140 without testosterone base or concurrent Enclomiphene/HCG creates a state where natural testosterone is suppressed without replacement. By mid-cycle: low testosterone + no estrogen = libido crash, mood dysregulation, potential muscle loss despite the RAD-140 AR signal, and joint discomfort from the hormonal deficit.
What to do:Not technically a stacking conflict, but the absence of the right stack is a meaningful protocol error. Users who insist on running solo should use concurrent Enclomiphene 6.25–12.5 mg/day or HCG 125–250 iu/day.
Why:Cardarine was abandoned in clinical development due to dose-dependent carcinogenicity in rodent studies. While the relevance to humans is debated, the risk-benefit calculation changes significantly for individuals with cancer history. RAD-140 itself is being studied for anti-cancer applications.
What to do:This applies to the Cardarine component of the stack, not RAD-140 itself. The RAD-140 + Cardarine recomp stack is popular but Cardarine's safety profile deserves independent evaluation.
Why:5-alpha reductase inhibitors prevent conversion of testosterone to DHT — they are effective for testosterone-driven androgenic alopecia. RAD-140 is not a 5-alpha reductase substrate (non-steroidal). Its androgenic effects on hair follicles are via direct AR agonism, not DHT conversion. 5ARi drugs do not protect against RAD-140-induced alopecia.
What to do:Use topical RU-58841 and Minoxidil 10% instead — these act at the follicle level where RAD-140's mechanism operates.
Protocols By Goal
Lean Bulk 10–20 mg/day RAD-140 for 8 weeks. Caloric surplus of 300–500 calories. Higher protein intake (1.8–2.2 g/kg body weight).
Keep carbohydrates moderate — the article's practical lane is lean/dry gain, not maximum scale weight. Expect 5–10 lbs lean mass if diet is disciplined. Common additions: MK-677 5–20 mg/day for GH-axis recovery/sleep support or LGD-4033 5–10 mg/day for more total AR stimulation, but either addition increases the support burden and LGD adds meaningful suppression.
Cut / Muscle Retention 10–15 mg/day RAD-140 for 8–10 weeks. Caloric deficit of 300–500 calories. Primary function: anti-catabolic protection during weight loss. RAD-140's muscle retention during caloric restriction is its most practical application for users who want to preserve strength and muscle on a cut. The lower dose keeps suppression and aggression pressure more manageable than the 20 mg lean-bulk lane.
Recomposition 15–20 mg/day RAD-140 for 8 weeks. Calories at or near maintenance (±200 calories). Simultaneous fat loss and lean mass gain are realistically plausible in community reports, but only when diet is controlled; large surpluses turn the cycle into a messier bulk. Cardarine (GW-501516) 10–20 mg/day is frequently stacked for endurance and fat-oxidation goals, but its separate carcinogenicity controversy should be evaluated independently.
TRT Augmentation 10–15 mg/day RAD-140 added to a stable testosterone base (TRT range or performance dose) for 8 weeks. Goal: additional anabolic stimulus on an existing testosterone plateau without raising testosterone dose. No PCT is required for users already remaining on exogenous testosterone, but LFTs, lipids, CBC, blood pressure, mood, and hairline signals still matter. This is the cleaner experienced-user frame than a natural solo cycle.
Women / Female Users Not recommended as a routine female anabolic protocol. The article's womenConsiderations section rates virilization risk high, pregnancy contraindicated, and the reviewed female evidence too thin to justify a positive RAD-140 lane. If exposure has already occurred, the task is harm reduction: stop at menstrual disruption, voice change, clitoral sensitivity/enlargement, acne surge, or hairline recession; monitor FSH, LH, estradiol, total testosterone, and symptoms through recovery rather than using a male PCT template.
Dosing Details
Dosing range: 5–30 mg/day oral; community consensus upper limit is 20 mg/day. Above 20 mg produces diminishing marginal muscle gains with disproportionately greater suppression and side effects.
Standard doses: - Conservative: 5–10 mg/day — reported by cautious first-timers or users stacking with other potent compounds; this is not a female recommendation. Measurable strength and lean mass benefits without maximizing suppression. - Standard: 15–20 mg/day — the most common dose in experienced community use. 20 mg/day is typically where the strength and body composition response plateaus before side effects outweigh benefits. - High-end (not recommended): 25–30 mg/day — reported by some community users; consistent reports of aggression, deeper suppression, and no significant additional muscle vs 20 mg. Not a validated or recommended approach.
Cycle length: - Bulking: 8 weeks. Diminishing returns typically begin after week 6; the 8-week mark is the established community ceiling for mass accumulation cycles. - Cutting/recomp: 8–10 weeks at lower doses (10–15 mg/day). Slightly longer cycles are tolerated when the dose is lower and the goal is muscle retention rather than accumulation.
Timing: Once daily in the morning. The ~60-hour half-life supports once-daily dosing. At 20 mg/day, splitting into 10 mg morning + 10 mg evening (12 hours apart) reduces peak/trough swings and maintains more consistent androgen receptor saturation. Daily use is the reported pattern because skipped doses disrupt steady-state exposure.
Administration: Oral only (liquid or capsule). Liquid and capsule formulations are reported; concentration accuracy and product identity are more important than taste or convenience details. Injectable RAD-140 ('Ragebolone') exists as an underground niche but has almost no systematic data and carries additional risks from non-sterile preparation.
Suppression management (mandatory): RAD-140 always suppresses the HPG axis. Three approaches: Reported management patterns include use alongside a testosterone base in already-suppressed/TRT contexts, concurrent fertility-preservation drugs in some natural users, or post-cycle SERM-based recovery attempts. None of these removes the need for bloodwork, and PCT success is not guaranteed; recovery is judged by post-cycle LH/FSH/testosterone trends, not by completing a template.
Liver support: Community liver-support practices include glutathione or bile-acid support, but these are not proof of protection. Avoiding hepatotoxic stacking and checking LFTs mid-cycle matter more given documented DILI cases.
Stacks & Alternatives
Complementary mechanisms: RAD-140 activates androgen receptor directly; MK-677 stimulates GH/IGF-1 release via ghrelin receptor agonism. Combined effect: AR-driven protein synthesis plus GH-driven recovery, collagen synthesis, and sleep quality. No additional suppression from MK-677. Ben Greenfield and other practitioners described this as a potent combination for muscle building and anti-aging.
Both are SARMs with anabolic profiles but different characteristics: LGD-4033 adds fuller/wetter mass gains while RAD-140 provides dry strength. Stacking allows higher total AR stimulation with dose moderation of each individual compound. Commonly dosed: RAD-140 10 mg + LGD-4033 5–10 mg. Suppression is additive — test base or aggressive PCT required.
Cardarine is not an androgen — it's a PPARδ agonist that enhances fat oxidation and endurance. Often stacked with RAD-140 for recomp: RAD provides anabolic/anti-catabolic stimulus while Cardarine maximizes fat burning and cardiorespiratory capacity. Note: Cardarine has animal carcinogenicity data that was reason for abandonment of clinical development — users should be aware of this risk.
YK-11 is a myostatin inhibitor and partial AR agonist — adds lean mass gains on top of RAD-140's strength stimulus. Short half-life (6–10 hours) requires split dosing. Stacked at 5–10 mg/day with RAD-140 10–15 mg/day for lean bulk purposes. Suppression is significant with this combination.
The most rational and responsible base for RAD-140 use. Testosterone replaces suppressed endogenous production, maintains libido, mood, erythropoiesis, and all other testosterone-dependent functions. RAD-140 adds its tissue-selective anabolic effect on top. Eliminates the suppression-management problem entirely.
Sometimes stacked at lower doses for joint-protective and mild anabolic synergy during cuts. Ostarine at 12.5–25 mg adds connective tissue support while RAD-140 handles muscle retention. Less suppressive than the RAD+LGD combination.
Alternatives
Stack Cost
High tax: RAD-140 is easy to swallow but hard to own responsibly; it creates a suppressive androgen lane with liver, lipid, mood, hairline, source-quality, anti-doping, and recovery obligations.
The article repeatedly frames suppression as dose- and duration-dependent, with solo users commonly hitting libido and low-testosterone problems by mid-cycle. RAD-140's selectivity does not spare the hypothalamus or pituitary.
Human DILI case reports, Phase 1 liver-function dose limits, HDL suppression concern, and a myocarditis case make CMP/LFTs and lipids more than cosmetic monitoring.
The required panel set spans baseline hormones, CBC, CMP/LFTs, mid-cycle liver checks, and post-cycle hormone recovery. Without labs, the user cannot distinguish a normal suppressive cycle from a dangerous one.
The article gives RAD-140 a stronger aggression/mood and hairline reputation than milder SARMs. Finasteride does not solve the hair issue because the mechanism is direct AR agonism.
Suppression conflicts with fertility planning in men, and the womenConsiderations section treats pregnancy, menstrual disruption, and virilization as hard constraints.
- ·Counts as a full suppressive SARM lane for natural users; do not layer another suppressive SARM unless the plan is being treated like an anabolic cycle.
- ·A testosterone base removes the natural-testosterone crash but does not remove RAD-140's liver, lipid, blood-pressure, mood, hairline, sourcing, or anti-doping tax.
- ·Do not extend beyond the article's 8-week core lane without new labs and a reason stronger than stalled progress chasing.
- ·Do not run with alcohol or 17-alpha-alkylated oral steroids because the liver-risk margin is already narrow.
- ·For women, do not frame this as a normal protocol option; exposure is harm-reduction only after an informed choice has already been made.
- ·Baseline total/free testosterone, LH, FSH, CBC, CMP with ALT/AST/ALP/GGT/bilirubin, and lipid panel.
- ·Mid-cycle LFTs around week 4, with hormone labs if running natural or trying to preserve HPG activity.
- ·Post-cycle hormone recovery labs 4-6 weeks after stopping or after PCT.
- ·A testosterone-base, enclomiphene/HCG, or PCT plan selected before the first dose.
- ·Alcohol and hepatotoxic-medication avoidance during the cycle.
The article's own Quick Read rates RAD-140 advanced because the useful dose range overlaps with suppression, documented hepatotoxicity, mood/aggression changes, hairline risk, and unapproved product-quality uncertainty.
- ·No willingness to run bloodwork.
- ·Under age 25 or still establishing a natural endocrine baseline.
- ·Trying to preserve fertility without a physician-supervised plan.
- ·History of liver disease, poor lipids, uncontrolled blood pressure, mood instability, or androgenic alopecia concern.
- ·Female user seeking an anabolic protocol rather than harm-reduction after exposure.
Stopping the oral dose is simple, but suppression, libido, mood, lipids, LFTs, and training-performance expectations can lag behind discontinuation. The article treats post-cycle labs as the recovery decision point.
- ·Low libido, fatigue, or mood drop if LH/FSH and testosterone do not restart cleanly.
- ·Need for enclomiphene, clomiphene, tamoxifen, HCG, or TRT evaluation depending on labs and symptoms.
- ·Delayed LFT or HDL normalization after a harder cycle.
- ·Strength drop when the peak weeks 3-6 performance window ends.
- ·Hair shedding or acne continuing after the cycle.
Use baseline and mid-cycle labs, keep the cycle bounded, and use a planned testosterone-base, HPG-support, or PCT strategy rather than improvising after symptoms appear.
Avoid alcohol and 17-aa oral AAS, run mid-cycle LFTs, and stop if liver markers or cholestatic symptoms move into a dangerous range.
Lower dose or stop rather than treating CNS aggression as proof the cycle is working.
Avoid if hair preservation is a priority; finasteride does not block direct RAD-140 AR activation in follicles.
RAD-140's central cost is suppression; starting from a fragile HPG baseline removes recovery margin.
The article documents RAD-140 DILI and Phase 1 LFT limits; liver risk should not be layered onto an already stressed baseline.
The article flags androgenic lipid pressure, FDA cardiovascular warnings for SARMs, and a myocarditis case report.
RAD-140 can activate follicle AR directly, and 5-alpha-reductase inhibitors do not remove that mechanism.
Practical Setup
Product quality: RAD-140 is unapproved for bodybuilding use, and non-prescribed products have significant identity, concentration, and contamination uncertainty. Third-party testing helps but does not make the category equivalent to an approved medicine.
Forms: Available as liquid (typically 10–20 mg/mL, PEG-400 or DMSO carrier) and capsules. Liquid and capsule products are reported; concentration accuracy and product identity are the practical issues.
Drug interactions: Avoid combining with hepatotoxic agents including alcohol, 17-aa oral steroids, and hepatotoxic medications. RAD-140 may interact with medications metabolized by CYP enzymes (androgen receptor modulators can affect CYP3A4 activity) — consult with a physician before use if on any regular medications.
Anti-doping: RAD-140 is on WADA's S1 prohibited list for all athletes. Detection window: the 60-hour half-life means the parent compound is detectable for several days; metabolites identified by German Sports University anti-doping researchers extend the detection window significantly beyond apparent pharmacokinetic half-life. Do not use RAD-140 if subject to drug testing in any regulated sport.
Biomarkers to monitor during cycle: - ALT, AST, GGT, bilirubin — liver safety (most critical) - Total testosterone, LH, FSH — suppression monitoring - Hematocrit — polycythemia monitoring - HDL cholesterol — cardiovascular lipid risk
Lipid management: RAD-140 suppresses HDL similarly to testosterone. If baseline HDL is already low (<40 mg/dL), additional cardiovascular monitoring and lipid-improving interventions (omega-3 supplementation, exercise programming) should be considered.
Mechanism Deep Dive
Androgen Receptor Binding and Tissue Selectivity RAD-140 is a non-steroidal AR agonist with Ki = 7 nM — approximately 4x higher affinity than testosterone (Ki = 29 nM) and comparable to or exceeding DHT (Ki ~10 nM) in tested models. Its pyrazole-oxadiazole scaffold (C20H16ClN5O2, MW 393.83) binds the ligand-binding domain of the AR but induces a different conformational change than steroidal ligands. This altered conformation is recognized differently by co-regulator proteins — co-activators and co-repressors — whose expression varies by tissue. In skeletal muscle: abundant co-activator recruitment → full agonism → anabolic gene transcription. In prostate and seminal vesicles: different co-regulator milieu → partial antagonism or blunted agonism. This tissue-specific co-regulator expression is the molecular basis of SARM selectivity, not a different receptor or binding mode.
Genomic (Nuclear) Pathway After oral ingestion and absorption, RAD-140 binds cytoplasmic AR. The ligand-receptor complex translocates to the nucleus, binds androgen response elements (AREs) in promoter regions of androgen-responsive genes, and recruits transcriptional co-regulators. This activates genes encoding muscle-specific proteins including skeletal alpha-actin, myosin heavy chain, and IGF-1 receptor — driving protein synthesis and myofibrillar hypertrophy. The non-genomic (rapid, membrane-level) AR signaling pathway is also active but less well characterized for RAD-140 specifically.
Neuroprotection RAD-140 crosses the blood-brain barrier and activates AR in neuronal tissue. In androgen-deprived conditions (orchidectomized rat models), AR agonism protects neurons from apoptosis and may support neurogenesis. The brain AR acts differently from muscle AR — the neuroprotective effect appears to involve Bcl-2 upregulation (anti-apoptotic protein) and BDNF modulation. This is a secondary mechanism with no established clinical translation to recreational users, but it is the basis for ongoing Alzheimer's disease research with RAD-140 and similar compounds.
HPG Axis Suppression Like all AR agonists — steroidal and non-steroidal — RAD-140 suppresses the hypothalamic-pituitary-gonadal axis via negative feedback. Hypothalamic GnRH secretion decreases in response to elevated androgen signaling, reducing pituitary LH and FSH release, which in turn reduces testicular testosterone production. The degree of suppression is dose- and duration-dependent. RAD-140's claim to 'selective' action does not extend to HPG axis sparing — the pituitary and hypothalamus are not spared from feedback suppression.
Non-Aromatization RAD-140's non-steroidal scaffold has no substrate activity for the aromatase enzyme (CYP19A1). No estrogen is produced from RAD-140 metabolism. This means: no aromatase-mediated estrogenic side effects (gynecomastia, water retention) and no estrogen-mediated benefits (joint lubrication from elevated estrogen, bone protection via estrogen pathway, full libido support via estradiol). This is why experienced users frame RAD-140 as an anabolic supplement to testosterone rather than a testosterone replacement.
Bone Effects Osteoblast activation and osteoclast suppression are documented in orchidectomized rat models (Budaya et al. 2025) — consistent with AR agonism in bone tissue. The expected mechanism: AR activation in osteoblasts promotes bone formation gene expression; reduced androgen-driven osteoclast activation from suppressed endogenous testosterone is offset by RAD-140's direct AR agonism in osteoblasts. Short-term (14-day) studies in healthy young rats (Puskas et al. 2025) showed no significant cortical or trabecular bone architectural changes at micro-CT — suggesting bone effects may require longer treatment duration or androgen-deprived baseline conditions.
Hepatotoxicity Mechanism Not fully characterized. The cholestatic pattern of DILI (elevated bilirubin, cholestatic hepatitis on biopsy) suggests interference with bile acid transport or canalicular secretion, possibly via AR-mediated effects on hepatic bile transporter gene expression. This is speculative — the published case reports document the phenotype but not the precise mechanism. The hepatotoxicity is not a class effect of all androgens; it appears specific to certain oral non-steroidal compounds including some SARMs and oral anabolic steroids via different but related mechanisms.
Evidence Index
Quantitative claims trace to these source studies. Population, dose, and study type matter — claims from HIV-lipodystrophy trials don't transfer cleanly to healthy adults; data from supraphysiologic doses doesn't apply at TRT.
The overview cites foundational characterization showing RAD-140 as a potent androgen receptor agonist with Ki = 7 nM versus testosterone's 29 nM, with muscle/bone anabolic effects and relative prostate/seminal-vesicle sparing in preclinical models.
Supports mechanism and tissue-selectivity rationale, not human bodybuilding efficacy or long-term safety.
The article states that a Phase 1 dose-escalation trial in ER+/HER2- metastatic breast cancer patients used 50-150 mg/day and established preliminary safety and antitumor activity, with liver-function elevations appearing as dose-limiting toxicity in related Phase 1 reporting.
These doses exceed common recreational 10-20 mg/day cycles, but the population and cancer context do not establish safety or anabolic effect for healthy lifters.
The article cites German Sports University anti-doping work measuring human pharmacokinetics and confirming an approximately 60-hour elimination half-life.
Useful for dosing frequency and detection-risk framing; it does not validate recreational cycle safety.
Community reports at 15-20 mg/day over roughly 8 weeks describe 10-25% strength increases and 5-10 lb lean-mass gain in intermediate lifters.
This is the main practical efficacy signal for physique use, but it is uncontrolled and confounded by diet, training, starting status, survivorship bias, and product uncertainty.
The adverse-effects section cites published RAD-140 drug-induced liver injury with cholestatic hepatitis, jaundice, elevated liver markers, biopsy confirmation, and normalization after discontinuation.
A case report cannot estimate incidence, but it justifies treating mid-cycle LFT and bilirubin monitoring as serious rather than optional.
The adverse-effects section notes additional severe DILI reports with bilirubin peaks up to 38.5 mg/dL.
Supports severity framing for cholestatic injury, but exact product identity, dose, and contamination context should be verified before using this as a precise incidence claim.
The article cites an acute myocarditis case in a 22-year-old SARM user with troponin 100.5 ng/mL and left ventricular ejection fraction 15%.
Mechanism and product contamination remain uncertain, so this supports red-flag sensitivity rather than a quantified RAD-140-specific cardiovascular rate.
The observed-effects section states that RAD-140 increased muscle fiber cross-sectional area in unstimulated limbs in Sprague-Dawley rats over 14 days.
Mechanistic support for androgen-mediated hypertrophy independent of loading; not direct human efficacy evidence.
The observed-effects section states that in orchidectomized Wistar rats over 6 weeks, RAD-140 increased osteoblast count, myonuclei number, and muscle fiber cross-sectional area while decreasing osteoclasts.
Supports anti-catabolic bone-muscle mechanism in androgen-deprived animals, not a human physique protocol.
Not medical advice. PepTutor summarizes fallible research and community signal for trained practitioners; some compounds are research-only, unapproved, controlled, jurisdiction-dependent, or labeled not for human consumption.