Andarine (S4)

S-4, GTx-007

SARMs & research compoundsNot approved for humansWADA S1.2 · prohibitedEvidence: limited human data

An early non-steroidal SARM from GTx, a partial androgen-receptor agonist; development stopped after early human trials, reportedly over vision problems.

What it gives

What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.

Purpose

Taken on a diet for a 'dry', hard look and to keep muscle. Once developed for muscle wasting, osteoporosis and prostate enlargement; only early, unpublished human trials were done.

What people seek and what studies show

Users want to hold muscle and look dry and hard while dieting. In castrated rats it restored muscle mass and strength and raised bone density more than DHT, with little effect on the prostate, while lowering LH and FSH. Its early human trials were never published, so none of the muscle, strength or 'dryness' effects users describe are documented in people. Tinted, poor night vision is what it is actually known for.

Effects

Keeping muscle in a deficitFat lossHard, dry look

Evidence: Limited human data — some human studies, small or short

Sought effects by goal (as reported)

Cutting
Sought for: fat loss, keeping muscle in a deficit, hard, dry look
Recomposition
Sought for: fat loss, keeping muscle in a deficit
Endurance
Sought for: fat loss

Possible side effects

Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.

7 possible side effects

level · how often it is reported
Moderate
Vision changes
Yellow-tinted and poor night vision are widely reported; development reportedly stopped over them. Stop it and see an ophthalmologist; no night driving until vision is normal.
How to notice: Blurred vision, tinted vision, trouble seeing at night.
common
Moderate
Suppression of natural testosterone & fertility
A partial agonist, but it still lowers natural testosterone; how strongly in humans was never published.
How to notice: Lower libido and energy, smaller testicles; low natural testosterone on tests after stopping.
In women: Menstrual changes or missed periods, lower libido and energy; reduced fertility.
common
Moderate
Worse cholesterol (HDL↓ LDL↑)
No published human data for andarine; HDL drops are a consistent finding with oral SARMs.
How to notice: No symptoms — only visible on a lipid panel.
common
Moderate
Black-market quality risk (fakes, contamination)
In a JAMA analysis andarine turned up unlisted in products sold as ostarine or RAD-140, and one andarine product held far less than labeled.
How to notice: Unexpected effects, pain or infection, a stronger or weaker effect than expected.
common
Moderate
Liver strain
No human data; it is a close chemical relative of ostarine, which has caused cholestatic liver injury.
How to notice: Usually silent early; later tiredness, nausea, itch, dark urine.
possible
Moderate
Unknown long-term safety (little human data)
Human data are limited to unpublished early trials; long-term safety is unknown.
How to notice: Nothing to notice — the risk is what is not yet known.
possible
MenLow
WomenHigh
Virilization in women (often irreversible)
Despite its 'mild' image, it can virilize women at doses that affect muscle; voice changes may be permanent.
How to notice: Hoarse or deeper voice, new facial or body hair, menstrual changes, clitoral enlargement.
possible

What the levels mean

Lowbackground — just be aware
Moderatewatch for signs
Elevatedneeds regular control
Highcritical — can be life-threatening or permanent

Level: general category from the literature, not your personal risk

How often

common
reported often
possible
reported in some people
rare
reported occasionally

How to lower the risks

For 5 of 7 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. For the rest — general advice. No measure removes a risk completely.

ModerateVision changes

Stop and see an ophthalmologist at any vision change.

Measure
Working with a doctor
How each option helps (1)
  • Working with a doctor — Vision changes on clomiphene, tamoxifen, isotretinoin, PDE5 or GLP-1 drugs need prompt review; several labels advise stopping, which may limit lasting harm.
ModerateSuppression of natural testosterone & fertility

Check hormones before and after; if they stay low, see an endocrinologist.

Measure
Regular blood testsWorking with a doctor
How each option helps (2)
  • Regular blood tests — LH, FSH and testosterone show how deep suppression is and whether natural production has recovered afterwards.
  • Working with a doctor — Assesses how deep suppression is and guides recovery afterwards, including fertility testing.
ModerateWorse cholesterol (HDL↓ LDL↑)

Avoid combining several oral steroids; regular cardio, soluble fiber (psyllium), less saturated fat and alcohol; if LDL/ApoB stay high, a doctor may consider a statin. Omega-3 only lowers triglycerides.

Measure
Regular blood testsWorking with a doctorAvoiding alcohol and other liver stressorsRegular cardio training
How each option helps (8)
  • Regular blood tests — A lipid panel with ApoB shows how far HDL has dropped and LDL risen — changes you cannot feel.
  • Working with a doctor — Interprets lipids and ApoB and decides whether a statin or other therapy is warranted.
  • Avoiding alcohol and other liver stressors — Alcohol raises triglycerides; its small HDL bump does not lower heart risk.
  • Regular cardio training — Raises HDL a little and lowers triglycerides; it cannot offset a steroid-driven fall in HDL on its own.
  • Berberine — Placebo-controlled meta-analysis: LDL about 0.5 and triglycerides about 0.4 mmol/L lower; HDL unchanged. Trials are mostly small; no statin substitute.
  • Citrus bergamot — Pooled small trials show lower LDL and triglycerides, but certainty is low to very low; it is no replacement for statins.
  • Omega-3 (fish oil, EPA/DHA) — Clearly lowers triglycerides but does not fix the steroid HDL drop, the main lipid harm; DHA-containing oils may even raise LDL slightly.
  • Psyllium husk fiber — Lowers LDL by about 0.2–0.3 mmol/L (roughly 5–10%), also on top of doctor-prescribed statins; no effect on HDL.
ModerateBlack-market quality risk (fakes, contamination)

Products obtained without a prescription are often fake, mislabeled or non-sterile, and there is no way to check at home. For legal supplements, look for third-party testing (Informed Sport, NSF).

ModerateLiver strain

No alcohol, no other liver stressors, limit oral steroids and their combinations, check liver enzymes.

Measure
Avoiding alcohol and other liver stressorsRegular blood tests
How each option helps (5)
  • Avoiding alcohol and other liver stressors — Removes a major extra liver stressor during oral steroids and other hepatotoxic drugs.
  • Regular blood tests — ALT, AST, GGT and bilirubin show liver strain before symptoms; heavy lifting alone raises AST/ALT for days, and GGT helps tell muscle from liver.
  • Ademetionine (SAMe) — Used for intrahepatic cholestasis in some countries, but trials are small and of low quality; untested in steroid users. Stopping the oral steroid matters most.
  • N-acetylcysteine (NAC) — Restores glutathione; proven in paracetamol poisoning and helped in early acute liver failure of other causes, but untested in steroid users.
  • TUDCA (tauroursodeoxycholic acid) — Improves bile flow in cholestatic disease; in steroid cholestasis only case reports, with failures in severe cases. Stopping the oral steroid matters most.
ModerateUnknown long-term safety (little human data)

What is unknown cannot be lowered, only avoided; tell your doctor what you have taken.

MenLow
WomenHigh
Virilization in women (often irreversible)

Stop at the first voice change and see a doctor — early stopping matters.

Measure
Working with a doctor
How each option helps (1)
  • Working with a doctor — Steroid labels say to stop at the first mild signs (hoarse voice, facial hair, clitoral growth) to prevent permanent change; checks catch them early but do not make use safe.

Check-ups and blood tests

Which tests and check-ups to do and when. This is a guide — agree the exact schedule with your doctor.

Baseline tests
your own starting values — every later result is compared with them
Lipid panel (HDL, LDL, triglycerides, ApoB)cholesterol, low estrogen
Liver panel (ALT, AST, GGT, bilirubin)liver
Testosterone (total, free), LH, FSH, SHBGnatural testosterone
Estradiol (sensitive assay)low estrogen
While taking
about 4–6 weeks in, then every 6–8 weeks — agree the exact schedule with your doctor
Lipid panel (HDL, LDL, triglycerides, ApoB)cholesterol, low estrogen
Liver panel (ALT, AST, GGT, bilirubin)liver
Estradiol (sensitive assay)low estrogen
After stopping
4–8 weeks after stopping (later after long-acting injections), then until values return to baseline
Lipid panel (HDL, LDL, triglycerides, ApoB)cholesterol, low estrogen
Liver panel (ALT, AST, GGT, bilirubin)liver
Testosterone (total, free), LH, FSH, SHBGnatural testosterone
Semen analysisnot earlier than 3 months after stopping, then every 3 months until normalnatural testosterone

Which doctors can help

Sports physiciancoordinates everything
Endocrinologistlow estrogen, natural testosterone
Cardiologistcholesterol
Gastroenterologist / hepatologistliver
Ophthalmologistvision
Gynecologistvirilization, natural testosterone (women)

Get medical help at once if

  • Yellow skin or eyes, dark urine, pale stools, intense itching, pain under the right ribs — see a doctor now; sudden severe abdominal pain with dizziness or fainting — call emergency services.
  • Sudden loss or blurring of vision, flashes, a curtain over sight — seek urgent care.
  • Deepening voice, new facial hair, clitoral enlargement — stop and see a doctor: changes can become permanent. (women)

In an emergency, call your local emergency number.

For women

Can virilize women at doses that affect muscle; voice deepening and clitoral enlargement may be permanent. The vision changes affect women equally.

Myth & fact

Myth

“S4's yellow vision is harmless.”

Fact

Users say it fades after stopping, but its cause was never studied, and poor night vision makes driving in the dark dangerous.

Combinations

No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.

Check combinations →

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