SARMsHigh risk

YK-11

Also known as: YK-11, YK11

Sold as a SARM, but it is a steroid — and a 17-alpha-methylated one, which means the liver risk everyone thinks they avoided by choosing SARMs is fully present here.

Substance family

SARMs

Non-steroidal compounds binding the same androgen receptor as testosterone, but favouring muscle and bone over prostate and hair. The selectivity is real; the suppression of the body's own production is not avoided by it. None is approved anywhere.

Effects on

Muscle & strength

Which outcomes this substance acts on — descriptive, not a recommendation.

Strain profile

Where this substance is most likely to hit — a rough orientation, individually dependent on dose, duration and predisposition.

Liver

high

Kidneys

minimal

Blood lipids

high

Hematocrit

minimal

Blood pressure

low

Hormonal axis

high

This substance causes

Own production suppressed Liver strain HDL drops, LDL rises

Dosing & protocols by goal

Rough orientation ranges as reported in harm-reduction literature — not an individual treatment plan. Doses are individual and open-ended; frequency depends on the ester or half-life.

Human clinical data

Medical

Dose

Does not exist

Frequency

—

Cycle length

—

YK-11 has never been studied in humans. What exists is cell culture work from 2011 onward — not even animal studies in any meaningful number.

Grey market practice

Not a recommendation

Dose

5–10 mg / day reported

Frequency

Split into 2 doses

Cycle length

4–6 weeks reported

The short durations circulating are an acknowledgement of the liver burden, not caution about the compound itself. Doses come from user reports with no research basis whatsoever.

Supraphysiological doses carry significant health risks and are not legal without a medical indication. This information serves education and harm reduction, not as a usage recommendation. Accompanying blood work and — where relevant — a post-cycle plan (PCT) are essential. See the disclaimer.

Side effect & countermeasure

Typical problems and what you can do to reduce harm — at a glance. Does not replace medical monitoring.

Problem

It is not a SARM — it is a 17-alpha-methylated steroid

Countermeasure

The single most important fact about this compound, and the one the label conceals. YK-11 has a steroid backbone derived from DHT and carries a 17-alpha methyl group. That is the same modification that makes methandienone, stanozolol and oxymetholone liver-toxic. Anyone who chose SARMs specifically to avoid oral steroid liver strain has, with YK-11, bought exactly what they were avoiding.

Problem

Liver strain

Countermeasure

Follows directly from the 17-alpha-alkylation. Liver values before, during and after; TUDCA at 500 mg daily supports bile flow and NAC works on a separate mechanism. No alcohol, no other oral compounds alongside. Persistent itching without a rash, dark urine or pale stool point to cholestasis and mean stop immediately.

Problem

The myostatin claims rest on cell cultures

Countermeasure

The follistatin and myostatin data come from muscle cells in a dish. That is a legitimate starting point for research and not evidence of an effect in a person. No human has ever been measured on this compound in a study. Every account of what it does is anecdote.

Problem

Severe suppression

Countermeasure

As a steroidal androgen receptor agonist it suppresses the axis fully, and reports suggest more heavily than the dose would suggest. PCT with enclomiphene or clomiphene, bloodwork before and after, and the understanding that recovery here is not quick.

Problem

Harsh effect on lipids

Countermeasure

The combination of an oral 17-alpha-alkylated compound and strong androgen receptor activity produces one of the worse lipid profiles in this category. A full panel is not optional, and values that collapse are a reason to stop rather than to add omega-3 and continue.

Overview

YK-11 is the clearest example of why the SARM label is a marketing category rather than a chemical one.

It is sold alongside ostarine and LGD-4033, discussed in the same forum threads, and bought by people who chose SARMs specifically because they are not steroids. YK-11 is a steroid. It has a steroid backbone, it is 17-alpha-methylated, and it carries the liver risk that comes with that.

What It Actually Is

Chemically, YK-11 is a derivative of dihydrotestosterone with a distinctive structure that includes a 17-alpha methyl group.

That group matters enormously and is the reason this page exists in this form. 17-alpha-alkylation is the modification that lets an oral steroid survive first-pass metabolism in the liver — by making it resistant to the breakdown the liver would otherwise perform. It is the defining feature of methandienone, stanozolol, oxymetholone and every other liver-straining oral. YK-11 has it.

So the reasoning "I take SARMs because I do not want to damage my liver with orals" fails completely here, and most people using it do not know that.

The Myostatin Story

The interest in YK-11 comes from a different claimed mechanism. Myostatin is a protein that limits muscle growth — a brake the body applies to keep muscle mass within bounds. Follistatin blocks myostatin. In cell culture experiments, YK-11 increased follistatin expression in muscle cells more than DHT did.

If that translated to humans, it would be genuinely novel: androgens work by pressing the accelerator, while blocking myostatin would mean releasing the brake.

The problem is the distance between a petri dish and a person. Cells in culture have no liver, no hormonal feedback, no blood supply and no systemic regulation. Countless compounds show impressive effects in that setting and nothing at all in a body. There are no human trials of YK-11, and essentially no animal work either.

What circulates as knowledge about YK-11 is therefore anecdote layered on a cell culture paper.

An Honest Assessment

Set aside the label and look at what is on offer: an unapproved research chemical, made without oversight, never tested in a human or a meaningful animal model, carrying the liver-toxic modification of oral steroids and suppressing the hormonal axis fully.

Against that, an actual oral steroid with decades of human data at least offers a known dose-response, a known side-effect profile and a known recovery timeline. That is not an endorsement of oral steroids — it is a statement that YK-11 has all of their downsides plus complete uncertainty.

If the goal is the myostatin mechanism specifically, the honest answer is that no substance available to a consumer has been shown to do this in humans.

Side Effects & Risks

Liver strain from 17-alpha-alkylation, including cholestasis
Severe HDL suppression, rising LDL
Full suppression of the body's own production
Joint discomfort and dry joints reported
Aggression, irritability
Hair loss in those predisposed
No manufacturing oversight; contamination and mislabelling are common

Blood Work & Monitoring

Liver values (ALT, AST, GGT, bilirubin) — before, during and after; this is the primary concern
Lipid profile (LDL, HDL, ApoB)
Total and free testosterone, LH, FSH
Estradiol (sensitive assay)
Blood pressure

Legal status by region

Regulation differs considerably between jurisdictions and changes over time. This is a rough orientation, not legal advice — check the rules that apply where you are.

Region	Regulatory status
United States	Not approved; FDA warning issuedSold under the SARM label, to which the FDA warnings apply.
EU / UK	No marketing authorisationNeither a medicine nor a supplement — no legal route for human use.
Most other jurisdictions	Unregulated grey area
Competitive sport	Prohibited at all timesCovered by WADA S1 as an anabolic agent.

All content on this page is for information and harm-reduction purposes only. It is not medical advice, not a recommendation to purchase or use, and does not replace consulting a doctor. Legal status and enforcement vary by country and change; verifying the current rules in your own jurisdiction is your responsibility. For adults 18+ only. See the full disclaimer.