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Synthetic nootropics & research compounds

YK-11

YK-11, steroidal selective androgen receptor modulator research compound

YK-11 is a steroidal androgen-receptor research compound. Human benefit and safety studies are insufficient. Moderate risk (3/5) is a provisional editorial estimate with very-low confidence, based on its mechanism and indirect evidence from another SARM; it is not a measured human risk rate.

SyntheticMostly In Vitro EvidenceInsufficient EvidenceModerate Risk ProfileCardiovascular CautionLiver CautionHormonal Caution
Updated October 2026/5 min read/6 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

What YK-11 research actually shows

5

YK-11 is a synthetic steroidal compound studied as a selective androgen receptor modulator (SARM). Its cell-level receptor activity is a mechanism finding, not evidence of improved focus, strength or muscle growth in people.

Provisional risk estimate: moderate 3/55
Confidence is very low. Androgen-receptor activity makes hormonal effects plausible, so a low-risk description would understate that concern. The estimate is an inference from mechanism and another SARM, not observed YK-11 harm frequency. The likelihood, severity and reversibility of human effects remain unquantified; high or critical base risk is not established either. Product contamination and sport rules are separate cautions.

Human research is not the same as human safety evidence

2

A YK-11 administration study identified metabolites for doping-control tests. Detection research helps laboratories identify exposure; it does not demonstrate benefit or establish the duration of a useful effect.

Dosage evidence gap

2

No validated human dosage range or safety margin is established by the cited YK-11 research. A capsule strength is a label quantity, not a clinically established serving recommendation.

02

Names, aliases and forms

Common NameYK-11
Spelling VariantYK11
Cas Number1370003-76-1
Regulatory NameUNII Z9748J6B0R
Pubchem Cid119058028
Molecular FormulaC25H34O6
InchikeyKCQHQCDHFVGNMK-PQUNLUOYSA-N
03

Potential effects and evidence map

Cell studies demonstrate androgen-receptor activity. Human YK-11 metabolism research helps identify anti-doping markers, but does not establish efficacy or a safety margin. Hormone and lipid findings from LGD-4033 provide indirect class context only; they are not YK-11 clinical findings.

Effect domainMagnitudeGrade
Focus / attention5
UnknownConfidence: Low

YK-11 cell research does not establish a human focus or attention benefit.

Note A zero rating means no established benefit here, not proof of no effect.

0/5
E
04

Timing & effect horizon

Effect horizonUnknown
Unknown
Duration, half-life and cycle claims2

Reliable human effect onset, practical duration and elimination The time for blood levels to fall by half during the final elimination phase.Source are not established here. Urinary detection of metabolites cannot supply those values, and no evidence-based YK-11 cycle length follows from it.

05

Safety, side effects and risk profile

U.S. FDA class warning3
As of October 2026, the U.S. FDA warns that SARM bodybuilding products can cause serious harms, including liver injury, and are unapproved drugs rather than dietary supplements. This class/product warning is relevant context, but does not measure the risk of a defined dose of pure YK-11.
Pregnancy and reproductive uncertainty3
FDA warnings for SARM products include miscarriage and fertility concerns. YK-11-specific pregnancy, lactation and reproductive safety data are insufficient; these are targeted cautions, not measured risks for ordinary healthy-adult use.
Hormonal caution5
Confidence: Low

Provisional hormonal concern: YK-11 activates androgen receptors in cells. The likelihood, severity and reversibility of hormonal effects in humans are not established.

Note Very low confidence. This is an indirect editorial estimate, not measured incidence. LGD-4033 human findings cannot be transferred quantitatively to YK-11.

3/5
D
The Ykarine report is confounded3

After a stroke report, FDA testing found both labeled YK-11 and undeclared trendione in GE Labs Ykarine. The mixed-product report cannot establish that YK-11 alone caused the stroke or provide an incidence estimate.

What the indirect human evidence says6

In a 21-day placebo-controlled trial enrolling 76 healthy men, LGD-4033 produced dose-dependent suppression of testosterone and HDL cholesterol; measured changes returned to baseline after stopping. No drug-related serious adverse events occurred. LGD-4033 is a different, nonsteroidal compound: these results support a hormonal concern but cannot quantify YK-11 risk or predict recovery.

06

Interactions and cautions

Stacks and post-cycle regimens5

YK-11-specific interaction studies do not establish the safety of combining it with hormones, other SARMs or post-cycle products. Its androgen-receptor activity makes assumptions of hormonal neutrality inappropriate; no interaction probability or corrective regimen can be inferred.

07

Legal and regulatory status

United States regulatory context3

As of October 2026, FDA describes marketed SARM bodybuilding products as unapproved drugs, not dietary supplements. This is U.S. regulatory context; sale, import and possession rules require separate checks for the relevant country and product.

WADA-governed sport4

The 2026 WADA Prohibited List names YK-11 among SARMs under S1 anabolic agents, prohibited at all times in WADA-governed sport. This sport rule does not establish general possession or import law.

08

Practical buying and quality notes

  • The FDA Ykarine finding shows why a YK-11 label alone cannot verify contents. Look for batch-matched independent identity and undeclared-drug testing. A certificate can describe the tested sample; it does not establish human safety or validate every item sold.3
  • For capsule listings, compare capsule count and stated milligrams per capsule before comparing package prices. Verify unusual prices and stock directly with the retailer. A low normalized price does not establish purity, safety or suitability.3
  • FDA notes that products labeled for research use or not for human consumption may still be marketed to consumers. Such wording does not establish safety or U.S. approval.3
09

FAQ

Is there an established YK-11 dose?

2

No validated human dose is established by these sources. Seller instructions and label strengths cannot substitute for clinical dose-finding research.

How long should a YK-11 cycle last?

2

No evidence-based cycle length is established. A metabolism study measures elimination markers, not how long benefits last or when repeated use becomes safe.

10

References

  1. PubChem. Compound Summary for CID 119058028, YK-11.
  2. Piper T, Dib J, Putz M, Fusshoeller G, Pop V, Lagojda A, Kuehne D, Geyer H, Schaenzer W, Thevis M. Studies on the in vivo metabolism of the SARM YK11: Identification and characterization of metabolites potentially useful for doping controls. Drug Test Anal. 2018;10(11-12):1646-1656.
  3. U.S. Food and Drug Administration. Certain Bodybuilding Products Put Consumers at Risk of Heart Attack, Stroke, Serious Liver Damage, and More.
  4. World Anti-Doping Agency. The 2026 Prohibited List: International Standard.
  5. Kanno Y et al. YK11 Is a Partial Agonist of the Androgen Receptor. Biological and Pharmaceutical Bulletin. 2011;34(3):318-323.
  6. Basaria S et al. The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral, selective androgen receptor modulator, in healthy young men. J Gerontol A Biol Sci Med Sci. 2013;68(1):87-95.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.