SARMs
S-23
Also called S23
S-23 draws interest for a lean, defined look, visible veins and strength while cutting. Users compare its appearance effects with oral steroids, but those comparisons are personal accounts rather than head-to-head research. Sweating, mood changes and uncertain hormone recovery are part of the discussion; its rat contraception study does not make it human birth control.
Dosage & duration
One reported oral-use example, not a recommended or validated cycle.
One reported use
Reported use · unapproved regimen- Dose
- 20 mg total per day
- How often
- Split morning and evening
- How long
- 4 weeks in this account
One person’s account after eight weeks of RAD-140, with hCG co-use. It does not establish a common or safe regimen.
A plotted concentration cannot show recovery of testosterone or sperm production.
Beyond the transformation photo
Appearance does not establish recovery
-
The desired result
A leaner, more defined look and strength during a cut are reported goals.
-
Hormones and fertility
A photo or a positive experience cannot show whether either has recovered.
-
The birth-control claim
A rat experiment using S-23 with another hormone does not establish human contraception.
Why S-23 gets attention
The attraction is a muscular, sharply defined look while dieting. Community reports describe vascularity, strength and a sense of greater drive in the gym. Some compare it with Anavar or Winstrol, or say it looks leaner than RAD-140. Those are subjective comparisons, not evidence that S-23 is stronger, safer or better for a cut.
What the transformation stories leave out
People report enthusiastic results, night sweats, aggression and uncertainty about hormone recovery. Accounts may also involve testosterone, other SARMs or recovery drugs, including one person who used S-23 immediately after RAD. A photo cannot separate those exposures from training, diet and S-23, or show whether hormones and fertility recovered.
Why the birth-control claim is misleading
The original experiment studied male rats. S-23 reduced reproductive hormone signals; the contraception arm also used estradiol benzoate. Fertility returned in those animals after treatment ended. That does not establish reliable birth control, a human recovery timeline or a safe bodybuilding regimen. Do not rely on S-23 to prevent pregnancy.
Does feeling good settle the trade-off?
No. Some users describe feeling excellent while others report problems, and those accounts are not clinical safety checks. FDA warns that unapproved SARM products can cause serious harm. Neither another person’s uneventful course nor a planned recovery drug establishes how someone else will respond.
Model details: S-23 · relative timing
Compare timing and buildup for this compound. The values are not blood concentrations or a measure of strength.
Relative timing from animal research; a human blood profile is not established.
Timing assumptions and sources
Animal-derived oral terminal rate; not a human estimate validated by measurement.
One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.
- Timing half-life used
- 11.9 hours
- Absorption half-life assumed
- 2.975 hours
- Reference amount for the relative scale
- 1 mg
- Absorption half-life is assumed to be one quarter of the slower timescale (2.975 h); it is not a measured absorption parameter.
- A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
- Using 11.9 h as an illustrative shape is allowed only with animal-derived/assumed human status.
- Do not scale rat Cmax to human by body mass conversion.
- Jones et al 2009 preclinical S-23
Male Sprague Dawley rats 10 mg/kg IV/oral; oral half-life 11.9 h, IV 10.9 h; human fertility/PK not established.
s23-relative-timing-2026-10 · version 1
Safety and interaction notes Read the limitations and discuss clinical questions with a professional
- Aromatizes
- No
The principal contraception experiment used S-23 with estradiol benzoate in rats. It does not establish human contraception, safety or guaranteed fertility recovery.
Common questions
Is S-23 better than RAD-140 for a cut?
Some users prefer the leaner-looking result, while others report more size with RAD. The accounts involve different diets, training and other drugs. No controlled bodybuilding comparison identified here establishes a winner.
Is S-23 reliable birth control?
No. The original fertility experiment was in rats and combined S-23 with estradiol benzoate. It does not establish dependable contraception in people.
Does recovery in the rat study mean human fertility will return?
No. Recovery in that animal experiment cannot predict an individual human’s hormone or sperm recovery. Reported recovery-drug plans do not establish a guaranteed outcome.
Sources Labels, studies and notes behind this guide
Catalog evidence: Animal or laboratory research. This describes the type of evidence, not a clinical review of every claim.
Summary and fact source checks: 2026-10-10, 2026-10-07. This records source checking, not medical review of the whole page.
Notes on the quick facts
- Sought-after result
- Reported goal, not a demonstrated human treatment benefit.
- Main trade-off
- Fertility and hormone recovery cannot be predicted from a reported cycle.
- Contraception
- Animal combination research is not human birth control.
- 1. Jones et al. — S-23 rat study
Rat muscle and hormonal effects; fertility experiment combined estradiol benzoate. No human recovery guarantee.
- 2. FDA — SARMs are unapproved drugs
Full FDA warning read 2026-10-10. Class warning includes liver injury, sexual dysfunction and infertility; it does not estimate the risk of each individual SARM.
- 3. Jones et al 2009 preclinical S-23
Male Sprague Dawley rats 10 mg/kg IV/oral; oral half-life 11.9 h, IV 10.9 h; human fertility/PK not established.
- 4. FDA consumer update on SARMs
Current US status and class-level adverse-event warning; not a quantified risk estimate for each SARM.
Related compounds and examples
Related compounds
Ostarine (MK-2866 / Enobosarm)
Ostarine appeals to lifters who want to keep muscle while cutting or add modest size without injections. Reported experiences range from worthwhile strength and physique changes to disappointment. Its reputation as a mild SARM does not mean it avoids hormone, cholesterol or liver risks.
Ligandrol (LGD-4033)
Ligandrol attracts lifters looking for fuller muscles, size and strength without injections. The question that keeps coming up is how much of that fuller look remains after stopping. Human research found a lean-mass increase, alongside hormone and cholesterol changes; individual transformation reports cannot predict the result for another person.
Andarine (S4)
Andarine is sought for a harder, more defined look and strength during a cut, rather than dramatic weight gain. Users compare it with Anavar or Ostarine, but those comparisons are anecdotal. Yellow or green vision and difficulty seeing in low light are a distinctive concern in reports, not a harmless sign that the product is working.