Testosterone vs YK-11
FDA Approved vs Limited Research
monitor Researched · 90% Some users run a low-dose testosterone base (e.g., 100-150 mg/week TRT) alongside YK-11 to mitigate the hormonal suppression caused by YK-11's AR agonist activity. A testosterone base can help maintain libido, mood, and energy levels during the cycle. However, combining exogenous testosterone with a 17-alpha alkylated compound increases the overall hormonal and hepatic burden. Liver function and estradiol should be monitored closely.
Molecular Data
Testosterone YK-11
Weight 288.42 Da (base) 430.54 Da
Half-life ~8 days (cypionate) ~6-10 hours
Type Steroid hormone (C19H28O2) Steroidal selective androgen receptor modulator with myostatin-inhibiting properties (C25H34O6)
Key Benefits
Testosterone
01 Restoration of normal testosterone levels in hypogonadal men
02 Increased lean muscle mass and strength
03 Improved bone mineral density and reduced fracture risk
04 Enhanced libido, sexual function, and erectile quality
05 Improved mood, energy, motivation, and cognitive clarity
06 Reduction in body fat percentage, particularly visceral fat
07 Increased red blood cell production and oxygen-carrying capacity
08 Improved insulin sensitivity and metabolic health markers
YK-11
01 Dual mechanism combining partial AR agonism with myostatin inhibition via follistatin upregulation
02 May theoretically promote muscle growth beyond what AR activation alone can achieve by removing myostatin-mediated growth limits
03 Steroidal structure providing oral bioavailability without requiring injection
04 Partial AR agonist activity may confer tissue selectivity with reduced androgenic side effects compared to full agonists (theoretical, not demonstrated in vivo)
05 Short half-life allows for relatively rapid clearance if side effects necessitate discontinuation
Dosing Protocols
Testosterone
100-200 mg/week (TRT) / 1-2x per week (injectable)
TRT - Standard Replacement 100-200 mg/week 1-2x per week
TRT - Conservative Start 80-100 mg/week 2x per week (40-50 mg per injection)
TRT - Propionate Protocol 25-50 mg every other day Every other day or 3x per week
Performance Enhancement - Moderate 300-500 mg/week 2x per week
Performance Enhancement - Advanced 500-750 mg/week 2-3x per week
YK-11
5-10 mg/day / Twice daily (AM/PM split, oral)
Side Effects
Testosterone
Acne and oily skin (increased sebum production via DHT)
Water retention and bloating (estrogen-mediated)
Mild mood changes (irritability, increased assertiveness)
Increased hematocrit and hemoglobin (erythrocytosis)
Testicular atrophy (suppression of LH/FSH from exogenous testosterone)
Injection site pain, redness, or irritation
Increased body hair growth
Mild elevation in blood pressure
YK-11
Liver stress and enzyme elevation (ALT, AST) due to 17-alpha alkylated steroidal structure
Testosterone suppression (dose- and duration-dependent, expected in all users)
Joint dryness and discomfort (related to reduced estrogenic activity and potential drying effect)
Hair shedding (consistent with androgenic activity from the DHT-derived structure; may or may not be reversible)
Lipid disruption (HDL suppression, LDL elevation)
Reduced libido and mood changes secondary to hormonal suppression
Mild headaches, particularly during the first week
Contraindications
Prostate cancer (active or history of hormone-sensitive prostate cancer)
Breast cancer in males
Polycythemia (hematocrit above 54% at baseline)
Uncontrolled severe heart failure
Untreated severe obstructive sleep apnea
Desire for near-term fertility (without concurrent HCG/FSH)
Pregnancy or potential exposure to pregnant women (Category X)
Hypersensitivity to testosterone or any formulation components
Pre-existing liver disease or elevated liver enzymes at baseline (17-alpha alkylated compounds are contraindicated in hepatic impairment)
Hormone-sensitive cancers (prostate cancer or other androgen-responsive malignancies)
Pregnancy or potential pregnancy (teratogenic risk from androgen receptor agonism and hormonal disruption)
Breastfeeding
Age under 25 (incomplete endocrine system maturation and higher risk of lasting HPG axis disruption)
Concurrent use of other hepatotoxic compounds or medications (oral steroids, certain NSAIDs, statins, etc.)
Known cardiovascular disease (insufficient safety data)
Research Evidence
Testosterone YK-11
Status FDA Approved Limited Research
References 5 studies 4 studies
Latest June 2023 2013
FDA Approved Yes No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.