Finasteride is an oral prescription medication used to treat male pattern hair loss, known medically as androgenetic alopecia. It belongs to a class of drugs called 5-alpha reductase inhibitors. These drugs block the enzyme responsible for converting testosterone into dihydrotestosterone (DHT). Since DHT miniaturizes hair follicles in genetically susceptible men, reducing its levels helps prevent further hair loss and can promote regrowth. Starting this treatment requires specific medical clearance and a significant long-term commitment.
Criteria for Medical Suitability
The most important criterion for starting finasteride is a confirmed diagnosis of androgenetic alopecia from a healthcare provider. This diagnosis confirms the hair thinning is due to hormonal sensitivity, which is the type of hair loss the medication treats. Finasteride is indicated for use in men, typically those between 18 and 41 years of age with mild to moderate hair loss.
The common dosage for hair loss is a 1-milligram tablet taken once daily, distinct from the 5-milligram dose used for an enlarged prostate. Certain pre-existing health conditions serve as contraindications. Caution is necessary for patients with existing liver function issues, as the liver extensively metabolizes the drug.
Contraindications also include known hypersensitivity or certain drug interactions. Finasteride is absolutely contraindicated in women who are or may become pregnant due to the risk of causing birth defects in a male fetus. Treatment should only begin after a thorough medical history review and clearance from a qualified professional.
Optimizing Timing Based on Hair Loss Progression
Finasteride primarily works by stopping the progression of hair loss, and the timing of intervention directly impacts the final result. The drug stabilizes existing hair and inhibits the miniaturization process before follicles become permanently dormant. Consequently, starting the medication earlier in the hair loss process tends to yield the best outcomes.
The Norwood scale classifies the extent of male pattern baldness. Patients in early stages, such as Norwood stages 2 or 3, typically experience the most significant benefit. Intervention at this stage is optimal because the hair follicles are still viable and responsive to the reduction in DHT.
Starting treatment when hair loss is severe (Norwood stage 5 or higher) may prevent further loss but offers reduced capacity for significant regrowth. Finasteride cannot revive follicles that have been bald for many years due to irreversible tissue changes. The greatest therapeutic window is during the initial phases of thinning, aiming to stabilize the hairline and increase density before the loss becomes advanced.
Pre-Treatment Steps and Necessary Consultations
A medical consultation is necessary before a prescription can be written, ideally with a dermatologist or a primary care physician specializing in hair loss. This step establishes medical suitability and treatment expectations. A detailed history and physical examination will be performed to confirm androgenetic alopecia and rule out other causes of hair loss.
A crucial pre-treatment step involves establishing a baseline of the current state of hair loss. This includes taking standardized photographs of the scalp and performing a scalp assessment to monitor future changes accurately. For men over 50 or those with a family history of prostate issues, baseline blood work may be ordered for Prostate-Specific Antigen (PSA) levels.
Finasteride reduces serum PSA levels by approximately 50% within six months of treatment, which impacts prostate cancer screening. Establishing a pre-treatment baseline PSA is important for interpreting subsequent readings. To reflect the true level, the measured value must be doubled. This protocol ensures the medication does not mask the early signs of prostate cancer, integrating initial testing into long-term health monitoring.
Understanding the Long-Term Commitment
Once the decision to start finasteride is made, it must be understood as a long-term treatment, often a lifelong commitment for sustained results. The medication’s effect of lowering DHT levels in the scalp only lasts as long as the drug is taken consistently. This requires continued daily use to maintain any stabilization or gains achieved.
Finasteride’s effects take time to become visible due to the slow cycle of hair growth. Most patients see stabilization or a cessation of excessive shedding within three to six months of starting treatment. Measurable regrowth, if it occurs, typically becomes noticeable around nine to twelve months, with strongest results seen within the first year.
Stopping the medication causes the beneficial effects to reverse, and the hair loss process resumes. DHT levels return to pre-treatment concentrations, and any hair maintained or regrown will likely be lost within 12 months. The commitment is to a daily regimen that sustains the low DHT environment necessary for healthy hair follicles.