Can SARMs Cause Infertility? What the Science Really Shows

By Nick Paul Taylor

Published January 1, 2026 · Updated November 4, 2026 · 4 min read

Short answer: Yes – SARMs can cause temporary infertility, and in some cases, prolonged suppression. While they’re often marketed as “safer than steroids,” the endocrine disruption risk is very real.

Note: All information provided is in reference to authorised trials and theoretical data. This not health advice. SARMs are not authorised for use outside of research.

The Biological Mechanism (Why Fertility Drops)

SARMs suppress fertility through the HPG axis (hypothalamic–pituitary–gonadal axis) – the same control system affected by anabolic steroids.

Here’s the sequence:

1. SARMs bind to androgen receptors
2. The brain senses “high androgen activity”
3. Production of LH (luteinizing hormone) and FSH (follicle-stimulating hormone) drops
4. The testes receive less stimulation
5. Sperm production and testosterone output decline

This leads directly to:

• Reduced sperm count
• Lower sperm motility
• Temporary infertility

Even though SARMs are “selective,” they are not fertility-selective.

Which SARMs Are Worst for Fertility?

Not all SARMs suppress fertility equally. The risk depends on androgen receptor binding strength, half-life, tissue penetration, and dose-response dynamics. Some compounds behave closer to mild testosterone suppressors, while others function more like near-steroidal shutdown agents.

Below is the accurate clinical risk hierarchy based on human trials, endocrine markers, and real-world suppression data.

Severe Fertility Suppression (Highest Risk Tier)

These SARMs produce deep LH/FSH shutdown, often requiring medical-grade recovery.

S-23

• Often called a “SARM in name only”
• Produces near-total testosterone suppression
• Originally investigated as a male hormonal contraceptive
• Documented effects:
  • Near-zero LH and FSH
  • Testicular volume reduction
  • Rapid sperm suppression

Fertility Risk: Extremely high
Recovery Difficulty: Often prolonged without intervention

RAD-140 (Testolone)

• One of the highest androgen receptor affinities
• Strong CNS interaction
• Commonly stacked at aggressive doses

Effects seen in users and literature:

• Sharp testosterone crash
• Significant LH/FSH shutdown
• Delayed spermatogenesis recovery in repeated cycles

Fertility Risk: Very high
Recovery Difficulty: Moderate–high

LGD-4033 (Ligandrol)

• Only SARM with published human suppression data
• Clinical trial showed:
  • Suppression within 21 days
  • Dose-dependent testosterone reduction
• Intratesticular testosterone also falls – directly impairing sperm production

Fertility Risk: Very high
Recovery Difficulty: Moderate–high

Moderate Fertility Suppression (Middle Risk Tier)

These SARMs suppress fertility consistently, but typically allow faster recovery if cycles are controlled.

Ostarine (MK-2866)

• Widely considered “mild”
• Still suppresses LH & FSH in most users
• Common fertility effects:
  • Reduced sperm count
  • Reduced libido
  • Flattened testosterone rhythm

Fertility Risk: Moderate
Recovery Difficulty: Low–moderate

ACP-105

• Neuroactive SARM
• Mild peripheral androgenic effects
• Still induces measurable HPG suppression

Fertility Risk: Moderate
Recovery Difficulty: Low–moderate

Lower Fertility Suppression (But Not Non-Suppressive)

These compounds are often misunderstood as safe SARMs – they’re simply less aggressive.

Andarine (S-4)

• Partial agonist in some tissues
• Weaker total androgen signaling
• Still suppresses upstream hormones

Fertility Risk: Mild–moderate
Recovery Difficulty: Low

Short-Exposure, Low-Dose Research Use

When kept within:

• Sub-therapeutic doses
• Short exposure windows
• No stacking

Fertility Risk: Low but not zero

Fertility Suppression Ranking (Quick Reference)

SARM	Fertility Risk	Recovery Complexity
S-23	🔴 Extreme	🔴 High
RAD-140	🔴 Very High	🟠 Moderate–High
LGD-4033	🔴 Very High	🟠 Moderate–High
Ostarine	🟠 Moderate	🟡 Low–Moderate
ACP-105	🟠 Moderate	🟡 Low–Moderate
S-4 (Andarine)	🟡 Mild–Moderate	🟢 Low

Can SARMs Affect Female Fertility?

Yes – though research is far thinner.

Potential female risks include:

• Disrupted ovulation
• Cycle irregularities
• Androgenic hormone shifts
• Temporary anovulation

SARMs were never approved for female fertility safety, and pregnancy exposure is considered high risk.

Further reading: How long do SARMs stay in your system?

Do SARMs Cause Genetic Damage to Sperm?

There is no solid human evidence of permanent DNA damage from SARMs alone, but:

• Animal studies show testicular architecture changes
• Severe suppression can impact sperm quality
• Stacked use increases oxidative stress

So while most effects are hormonal, cellular-level risk cannot be ruled out.

Key Takeaways

• SARMs can cause temporary infertility
• Suppression happens via LH & FSH shutdown
• LGD-4033, RAD-140, and S-23 are the most suppressive
• Most users recover fertility after stopping
• Repeated cycles raise the risk of long-term reproductive suppression

FAQ

Extended FAQs: SARMs & Fertility

• Do SARMs lower sperm count?
  Yes. By suppressing LH and FSH, SARMs directly reduce sperm production during use.
• Can you get someone pregnant while on SARMs?
  Yes, but the probability may be reduced due to lower sperm count and motility.
• Which SARM is closest to a male contraceptive?
  S-23. It was specifically researched for male hormonal contraception due to its extreme suppression of spermatogenesis.
• Does low-dose Ostarine still affect fertility?
  Yes. Even low doses can suppress LH and FSH in sensitive users.
• Do SARMs affect sperm motility or just count?
  Both can be affected. Hormonal suppression lowers overall sperm quality, not just volume.
• Can SARMs cause azoospermia (zero sperm)?
  Rare, but possible with highly suppressive compounds like S-23
• Can SARMs affect sperm morphology (shape)?
  Indirectly, yes. Hormonal disruption can impair normal sperm development.
• Do SARMs damage the testes permanently?
  Most changes are reversible, but repeated deep suppression increases long-term risk.
• Does fertility return faster in younger users?
  Generally yes – younger men tend to recover LH, FSH, and sperm production faster.
• Can SARMs cause testicular shrinkage?
  Yes, particularly with RAD-140, LGD-4033, and S-23 due to reduced intratesticular testosterone.
• Is fertility recovery guaranteed after SARMs?
  No. Most recover, but not all – especially after repeated long cycles.
• Do SARMs affect erectile function as well as fertility?
  They can. Suppression-related low testosterone may impair erectile quality during or after a cycle.
• Are fertility risks dose-dependent?
  Absolutely. Higher dose = deeper suppression = longer recovery.
• Can SARMs impact future fertility even after recovery?
  Possibly, if heavy suppression is repeated over many years.

Written by

Nick Paul Taylor · Freelance

Freelance biopharma reporter

Nick Paul Taylor is a freelance reporter covering the global biopharma industry. Nick specialises in pharmaceutical research, biotechnology, drug regulation and medical technology, and has written for Fierce Pharma, Fierce Biotech and Endpoints News for fifteen years. Nick is a biology graduate of the University of York.