SARMs
Andarine (S4)
Also called S4 · Andarine
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.
Dosage & duration
One public self-report · oral S4
Beyond the gym
Definition goals and vision concerns
The desired look
-
Sharper definition
Some users seek a harder-looking physique and strength during a cut.
The reported concern
-
Colour and low-light vision
Accounts describe yellow or green tint and difficulty seeing in the dark.
No safe threshold established Animal studies cannot define a safe human course or exposure without vision effects.
What do users mean by a dry, hard look?
In S4 discussions, they mean sharper definition, noticeable pumps and a firmer-looking physique without chasing a much higher scale weight. People ask whether that look comes with useful strength gains or mostly a temporary cosmetic change. Reports cannot separate S4 from body-fat changes, training or other drugs.
Is it like Anavar or Ostarine?
Those comparisons help describe what readers hope to see, but they are not reliable rankings. One account describes strength during a cut but a milder effect than Anavar, alongside worsening yellow vision with more exposure. It does not establish a dose at which benefits are worth the risk.
Vision changes matter outside the gym
One six-week account describes difficulty seeing at night despite liking the physique results. Other people report their symptoms resolved, but that does not guarantee harmless or reversible effects for everyone. New vision changes need prompt medical assessment; sudden loss of sight is an emergency. Do not drive while vision is impaired.
Where the evidence stops
The muscle-and-bone study behind S4’s development used castrated rats. It cannot establish human muscle gain, a safe cycle or a safe threshold for vision effects. The amount displayed above is one reported example, with six weeks completed and eight planned. It is not a clinical protocol.
Model details: Andarine (S4) · 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
Approximately 4 h rat/dog preclinical time course; human timing explicitly unverified.
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
- 4 hours
- Absorption half-life assumed
- 1 hours
- Reference amount for the relative scale
- 1 mg
- Absorption half-life is assumed to be one quarter of the slower timescale (1 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.
- Do not call 4 h a human measured half-life.
- No human absolute profile identified; retain relative with assumed timing.
- Animal allometry/scaling is not validated by a dose-conversion formula alone.
- Kearbey et al 2004 S 4 inrats
Original controlled PK is oral gavage/IV in rats; dose-dependent oral bioavailability.
- S 4 rat PKfull text
Preclinical species, dose and formulation; not a human calibration.
andarine-relative-timing-2026-10 · version 1
Safety and interaction notes Read the limitations and discuss clinical questions with a professional
- Aromatizes
- No
The cited pharmacology and PK studies were in rats. They do not establish human safety; new visual symptoms after exposure warrant prompt medical assessment.
Common questions
Is Andarine a fat burner?
People seek definition and strength while cutting. That is a reported goal, not proof of direct fat loss in trained people.
Are the vision effects always temporary?
Some users report recovery after stopping, but there is no reliable evidence here that guarantees reversibility or excludes another eye problem. New visual changes warrant prompt assessment, and sudden loss of vision is an emergency.
Is Andarine the same as Cardarine?
No. Andarine is S4, discussed as a SARM. Cardarine is GW501516 and acts at a different target. Similar names and products marketed together do not make them interchangeable.
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
- Why people seek it
- These are reported goals; the key controlled research is in animals.
- Standout concern
- Users describe yellow or green tint and difficulty adjusting to darkness.
- Evidence gap
- Animal results cannot set a human dose or safe cycle.
- 1. Gao et al. — S4 muscle and bone study in rats
Primary abstract and figure captions read. Eight-week treatment in castrated rats restored muscle outcomes and affected LH/FSH; not a human physique, vision-safety or dosing study.
- 2. NHS — when vision changes need urgent care
Patient guidance on new visual changes and emergency care for sudden loss of sight. General eye-symptom guidance, not evidence of a particular S4 mechanism.
- 3. 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.
- 4. S4 muscle and bone study in rats
Primary abstract via Europe PMC: castrated rats, muscle/bone and endocrine effects; not human benefit or dosing.
- 5. FDA — SARMs warning
Unapproved status; safety not established by research-only marketing.
- 6. Kearbey et al 2004 S 4 inrats
Original controlled PK is oral gavage/IV in rats; dose-dependent oral bioavailability.
- 7. S 4 rat PKfull text
Preclinical species, dose and formulation; not a human calibration.
- 8. S-4 pharmacokinetics in rats
Original rat oral/IV study; species-specific absorption and elimination, not human calibration.
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.
Testolone (RAD-140)
RAD-140 appeals to lifters chasing stronger lifts, noticeable pumps and a muscular look without injections. Experience reports also describe disrupted sleep, hair shedding and blood-pressure concerns. Testolone is not testosterone, and its human cancer research does not establish a safe bodybuilding substitute.