MK-677, YK-11, and LGD-4033 SARMs Stacks
Our MK-677, YK-11, and LGD-4033 stack includes one discounted 30 mL, 25 mg/mL bottle of MK-677, one discounted 30 mL, 10 mg/mL bottle of YK-11, and one discounted 30 mL, 10 mg/mL bottle of LGD-4033. Stack the savings!
Key highlights
Product specifications
| Compound Class | Growth Hormone Secretagogue · Ghrelin Receptor (GHSR-1a) Agonist · Non-steroidal |
|---|---|
| Concentration | 25 mg/mL |
| Composition | USP-grade PEG-400 base, MK-677 (≥98% purity) |
| CAS Number | 159752-10-0 |
| Chemical Formula | C27H36N4O5S |
| Molar Mass | 528.66 g/mol |
| Half-Life | ~24 hours |
| Synonyms | Ibutamoren, MK-677, Nutrobal, MK-0677, L-163,191 |
| Volume | 30 mL per bottle (750 mg total) |
| Verified Purity | Batch-tested to 99.87% (HPLC) |
| Compound Class | Selective Androgen Receptor Modulator (SARM) · Steroidal · Androgen receptor partial agonist |
|---|---|
| Concentration | 10 mg/mL |
| Composition | USP-grade PEG-400 base, YK-11 (≥98% purity) |
| CAS Number | 1370003-76-1 |
| Chemical Formula | C25H34O6 |
| Molar Mass | 430.54 g/mol |
| Synonyms | YK-11, YK11 |
| Volume | 30 mL per bottle (300 mg total) |
| Verified Purity | Batch-tested to 98.76% (HPLC) |
| Compound Class | Selective Androgen Receptor Modulator (SARM) · Non-steroidal |
|---|---|
| Concentration | 10 mg/mL |
| Composition | USP-grade PEG-400 base, LGD-4033 (≥97% purity) |
| CAS Number | 1165910-22-4 |
| Chemical Formula | C14H12F6N2O |
| Molar Mass | 338.26 g/mol |
| Half-Life | ~24–36 hours |
| Synonyms | Ligandrol, LGD-4033, VK5211, Anabolicum |
| Volume | 30 mL per bottle (300 mg total) |
| Verified Purity | Batch-tested to 97.29% (HPLC) |
For laboratory research use only. Not for human or animal consumption.
View certificates of analysisIndependently verified
Each compound in this bundle is analyzed by an accredited US third-party laboratory before it ships.
Purity and identity confirmed by MZ Biolabs (Tucson, AZ), a US DEA-licensed analytical facility, via HPLC purity analysis and mass-spectrometry identity confirmation under GLP standards.
Our third-party certificates of analysis are published on our website — no login required.
MK-677 (Ibutamoren)99.87% pure
YK-1198.76% pure
LGD-403397.29% pure
Storage & handling
All three bottles are built to preserve compound integrity throughout your research timeline.
- Storage: Keep in a cool, dry place away from direct sunlight to maximize shelf life.
- UV-resistant glass bottles with fixed glass droppers to minimize degradation and avoid plasticizer (BPA) leaching.
- Tamper-proof seals to ensure integrity in transit.
- Graduated 1 mL glass pipette included with each bottle for precise measurement.
- Evaporation-resistant formulation and packaging for stable storage.
Why source this stack from Sports Technology Labs
Quality control across the research-compound industry is inconsistent, which makes third-party verification essential. A 2017 analysis published in JAMA examined 44 products marketed online as SARMs and reported wide gaps between labels and contents.
Source: Van Wagoner et al., JAMA, 2017 (ref. 4).
All three compounds verified by MZ Biolabs (Tucson, AZ), an accredited US laboratory, via HPLC and mass spectrometry.
Suspended in the highest grade carrier and bottled in America.
Prevents BPA leaching and avoids contamination from external tools.
Transparent business, standard payment methods, no misrepresentation.
What is in this stack?
MK-677 (Ibutamoren)
A non-peptide ghrelin receptor (GHSR-1a) agonist and growth hormone secretagogue. Mechanistically, it binds and activates the GHSR-1a receptor — the same receptor targeted by the endogenous peptide ghrelin. It is orally bioavailable in study models and has been an investigational compound since the 1990s. It is not a SARM (ref. 1).
YK-11
A synthetic steroidal compound that acts as a partial agonist of the androgen receptor in vitro. It is commonly catalogued among SARMs and was first described in the research literature by Kanno et al. in 2011 (ref. 2).
LGD-4033 (Ligandrol)
A non-steroidal selective androgen receptor modulator (SARM). Mechanistically, it binds the androgen receptor with high affinity and tissue selectivity, distinguishing it from steroidal androgens. It was originally developed as an investigational compound by Ligand Pharmaceuticals (ref. 3).
All three compounds remain experimental research chemicals, supplied strictly for laboratory research. Sports Technology Labs makes no claims regarding their effects, and nothing in this listing should be interpreted as describing outcomes in humans or animals.
Important regulatory information
MK-677, YK-11, and LGD-4033 are investigational compounds. They are not approved by the FDA and are not dietary supplements, drugs, or food. Marketing them for human ingestion is unlawful.
All three are prohibited by the World Anti-Doping Agency: YK-11 and LGD-4033 under S1 (Anabolic Agents — SARMs), and MK-677 under S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics), banned in- and out-of-competition (ref. 5).
In the United States, none is a federally controlled substance and all may be legally purchased and possessed for laboratory research use. YK-11’s legal status differs in some other countries, where it may be restricted.
Sports Technology Labs are chemical suppliers, not medical providers. We do not condone or encourage consumer use of research compounds.
Scientific references
- Patchett AA, et al. Design and biological activities of L-163,191 (MK-0677): a potent, orally active growth hormone secretagogue. Proc Natl Acad Sci USA. 1995;92(15):7001–7005.
- Kanno Y, Hikosaka R, Zhang SY, et al. (17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester (YK-11) is a partial agonist of the androgen receptor. Biol Pharm Bull. 2011;34(3):318–323.
- 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.
- Van Wagoner RM, et al. Chemical composition and labeling of substances marketed as SARMs and sold via the internet. JAMA. 2017;318(20):2004–2010.
- WADA Prohibited List (2025), Sections S1 (Anabolic Agents — SARMs) and S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics). WADA.org.
Research use only. All products on this website are intended exclusively for laboratory research and development. They are not for human or animal consumption. These statements have not been evaluated by the U.S. Food and Drug Administration, and these products are not intended to diagnose, treat, cure, or prevent any disease.
