Finasteride vs MK-2866
FDA Approved vs Moderate Research
avoid Mechanism-based · 64% Both Finasteride and MK-2866 carry hepatotoxic risk. Combining hepatotoxic compounds significantly increases liver damage potential. If unavoidable, include liver support (TUDCA/NAC) and monitor ALT/AST frequently.
Molecular Data
Finasteride MK-2866
Weight 372.54 Da 389.33 Da
Half-life 6-8 hours (DHT suppression persists ~24 hours) ~24 hours
Type Synthetic 4-azasteroid compound Non-steroidal selective androgen receptor modulator (C19H14F3N3O3)
Key Benefits
Finasteride
01 Reduces scalp DHT by approximately 66% at 1mg daily
02 Slows or stops hair loss progression in roughly 90% of men
03 Produces visible hair regrowth in approximately 48% of men within 1-2 years
04 FDA-approved with over 25 years of clinical use and long-term safety data
05 Convenient once-daily oral dosing with no injections required
06 Well-characterized side effect profile with low incidence of adverse events
07 Can be combined with minoxidil for enhanced efficacy
MK-2866
01 Increases lean body mass in a dose-dependent manner with clinical trial support
02 Preserves muscle mass during caloric deficit or catabolic conditions
03 Selective tissue activity reduces androgenic side effects compared to anabolic steroids
04 Oral bioavailability eliminates the need for injections
05 Does not aromatize to estrogen, avoiding gynecomastia and water retention
06 Improves physical function and stair-climbing power in clinical populations
07 Long 24-hour half-life allows convenient once-daily dosing
08 Mild side effect profile at commonly studied doses
Side Effects
Finasteride
Decreased libido (reported in 1.8% of men in clinical trials vs 1.3% placebo)
Erectile dysfunction (reported in 1.3% vs 0.7% placebo)
Decreased ejaculate volume (reported in 0.8% vs 0.4% placebo)
MK-2866
Mild testosterone suppression (dose-dependent, typically 10-30% reduction at 25 mg)
HDL cholesterol reduction (10-20% suppression observed in clinical trials)
Headaches, particularly during the first 1-2 weeks
Mild back pain or muscle cramps
Transient fatigue toward the end of longer cycles
Slight reduction in libido at higher doses or extended cycle lengths
Contraindications
Women who are pregnant or may become pregnant (finasteride is teratogenic and can cause abnormalities of external genitalia in a male fetus; even handling crushed tablets poses a risk)
Women who are breastfeeding
Known hypersensitivity to finasteride or any component of the formulation
Severe hepatic impairment (finasteride is metabolized by the liver)
Pediatric patients (not indicated for use in children)
Active liver disease or significantly elevated liver enzymes
Hormone-sensitive cancers (breast, prostate) without oncologist clearance
Pregnancy or breastfeeding (potential endocrine disruption to fetus/infant)
Individuals under 21 years of age (risk of premature HPTA disruption during development)
Concurrent use of hepatotoxic medications without liver function monitoring
Known hypersensitivity to MK-2866 or any formulation excipients
Competitive athletes subject to WADA or USADA anti-doping testing
Research Evidence
Finasteride MK-2866
Status FDA Approved Moderate Research
References 5 studies 5 studies
FDA Approved Yes No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.