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S-23

S-23
Advanced Only Severe Suppression
Anabolic / Androgenic
100 15
6.7:1 vs testosterone baseline
Aromatizes No
Hepatotoxic No
Oral Yes
Suppression severe
PCT Required

S-23 is the most anabolic SARM produced by GTX and was investigated as a non-hormonal male contraceptive because it completely suppresses spermatogenesis. In practice its physique changes rival low-dose Trenbolone with far fewer androgenic issues.

Protocol Why Use It Comparison Safety
Warning
Highly suppressive – aggressive PCT mandatory · Darkened urine and cramps reported at high doses
Why people use it

S-23 is generally chosen by users who want a very aggressive SARM and are willing to accept that the line between ‘SARM’ and ‘steroid-like downside’ becomes blurry fast.

Protocol & usage

Administration: Oral compound. Most users take it with a fixed daily schedule rather than chasing short-term effect swings.

Cycle context: Treat this like a suppressive research drug, not a harmless shortcut. Labs before and after matter even when the compound is marketed as mild.

Stop or reduce if: blood pressure climbs, sleep degrades, libido crashes, or labs move sharply in the wrong direction.

Notes

Physique Effects

  • Recomposition King: Simultaneous fat loss and lean-mass gain; users report harder density within 10 days.
  • Extreme Dryness: Zero aromatization leads to grainy appearance; for shoot or stage.
  • Strength Drive: CNS stimulation improves aggression and power output.

Cycle Framework

Experience Dose Length Stack Idea
Intermediate 10 mg ED 4-6 wk Pair with 150 mg Testosterone for libido & joints.
Advanced 15-25 mg ED 4 wk Add 20 mg Anavar for additional polish.

Side-Effects & Management

  • Suppression: Severe: expect testicular shrinkage inside 14 days; pre-PCT hCG + full PCT mandatory.
  • Dark Urine & Cramps: Stay hydrated and supplement electrolytes (esp. potassium).
  • Mood: Some users note irritability akin to strong DHTs; monitor and adjust dose.

Bottom Line: S-23 offers near-tren recomp results in an oral format but demands serious post-cycle recovery planning and health monitoring.

Common mistakes

The big mistake is treating it like a step before real compounds instead of acknowledging that it already has a heavy suppression and recovery profile. Another is pairing it with other suppressive agents without a clear reason.

Comparison notes

Compared with RAD-140 or LGD-4033, S-23 usually lives at the harsher end of the SARM spectrum and is much less appropriate for experimentation.

Safety & monitoring
Side effects

  • Natural suppression with reduced fertility and testicular output

  • Suppression, worsened lipids, and an evidence base that is much thinner than users assume

Monitoring

  • CBC / hematocrit

  • blood pressure

  • lipid panel

Avoid if

  • Uncontrolled hypertension or untreated cardiovascular disease

  • Pre-existing severe infertility concerns unless that risk is accepted and managed

  • First-cycle or low-experience use

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