Finasteride vs Nandrolone
FDA Approved vs FDA Approved
avoid Researched · 95% DO NOT combine. This is one of the most misunderstood drug interactions in anabolic steroid use. Nandrolone is normally converted by 5-alpha reductase to dihydronandrolone (DHN), a much weaker androgen that is protective in androgen-sensitive tissues. Finasteride (and dutasteride) block this conversion, preventing nandrolone from being reduced to the weaker DHN. This leaves the more androgenic parent compound -- nandrolone itself -- to act unopposed on hair follicles, skin, and the prostate. The result is the exact opposite of the intended effect: hair loss is WORSENED, not prevented. Acne and prostate stimulation also increase. Unlike testosterone, where finasteride reduces androgenic load by blocking conversion to the more potent DHT, with nandrolone the 5-alpha reduced metabolite (DHN) is the weaker compound, so blocking 5-alpha reductase removes a protective pathway. This applies equally to finasteride and dutasteride. If you are using nandrolone and are concerned about hair loss, the solution is to lower the nandrolone dose or discontinue it -- not to add a 5-alpha reductase inhibitor.
Molecular Data
Finasteride Nandrolone
Weight 372.54 Da 274.40 Da (base)
Half-life 6-8 hours (DHT suppression persists ~24 hours) ~6-12 days (decanoate)
Type Synthetic 4-azasteroid compound 19-nortestosterone steroid (C18H26O2)
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
Nandrolone
01 Significant increases in lean muscle mass with a favorable anabolic-to-androgenic ratio
02 Enhanced collagen synthesis and joint lubrication, reducing joint pain and improving connective tissue integrity
03 Increased bone mineral density through direct osteoblast stimulation
04 Improved nitrogen retention and protein synthesis for accelerated recovery
05 Stimulation of erythropoietin production, increasing red blood cell mass and oxygen delivery
06 Lower androgenic side effects (hair loss, acne, prostate enlargement) compared to testosterone
07 Clinically demonstrated efficacy in treating anemia of chronic renal failure
08 Potential neuroprotective properties observed in preclinical research
Dosing Protocols
Finasteride
1mg/day (hair loss) or 5mg/day (BPH) / Once daily
Nandrolone
100-200 mg/week (therapeutic) / 1x per week (decanoate) or 2-3x per week (NPP)
TRT Adjunct - Joint Support 50-100 mg/week 1x per week (decanoate)
Therapeutic - Anemia / Wasting 100-200 mg/week 1x per week (decanoate)
Performance Enhancement - Moderate 200-400 mg/week 1x per week (decanoate) or split into 2 injections
NPP Protocol - Shorter Cycle 200-350 mg/week Every other day or 3x per week
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)
Nandrolone
Suppression of natural testosterone production (profoundly suppressive, more so than testosterone alone)
Water retention and bloating (less than testosterone at equianabolic doses)
Erectile dysfunction and reduced libido without concurrent testosterone ('deca dick')
Increased appetite and weight gain
Mild acne and oily skin (less pronounced than testosterone)
Elevated hematocrit and hemoglobin (erythrocytosis)
Injection site pain or discomfort
Mild mood changes (some users report increased emotional sensitivity)
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)
Prostate cancer (active or history of hormone-sensitive prostate cancer)
Breast cancer in males or females
Pregnancy or potential for pregnancy (Category X - causes virilization of female fetus)
Nephrosis or the nephrotic phase of nephritis
Severe hepatic impairment
Hypercalcemia
Known hypersensitivity to nandrolone or any formulation components
Polycythemia (hematocrit above 54% at baseline)
Uncontrolled heart failure or severe cardiovascular disease
Research Evidence
Finasteride Nandrolone
Status FDA Approved FDA Approved
References 5 studies 5 studies
Latest — April 2005
FDA Approved Yes Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.