What is the optimal dose of finasteride for hair loss?

Key Concepts:

Finasteride: A medication used to treat hair loss (androgenetic alopecia) and benign prostatic hyperplasia (BPH).
DHT (Dihydrotestosterone): A hormone that contributes to hair loss in individuals with androgenetic alopecia.
5-alpha-reductase (5-AR): An enzyme that converts testosterone into DHT. Finasteride inhibits this enzyme.
Dose Titration: Adjusting the dosage of a medication to find the optimal balance between efficacy and side effects.
Serum DHT: DHT levels in the blood.
Scalp DHT: DHT levels in the scalp tissue.
Phototrichogram: A method used to measure hair density and growth.
Norwood Scale: A classification system used to measure the stages of male pattern baldness.
Aromatization: The conversion of testosterone to estrogen by the aromatase enzyme.
Outcome Data vs. Mechanistic Data: Outcome data refers to the results observed in clinical trials, while mechanistic data refers to the theoretical understanding of how a treatment works.
Double-blind placebo-controlled study: A study where neither the participants nor the researchers know who is receiving the active treatment and who is receiving the placebo.

Optimal Finasteride Dosage for Hair Loss

1. Introduction:

The video addresses the question of the optimal finasteride dose for treating hair loss, clarifying conflicting information about effective dosages.
It contrasts scientifically-backed treatments with unsubstantiated ones.

2. Rationale for 1mg Finasteride Dose:

The standard 1mg daily dose is based on the initial clinical trials that led to Propecia's approval for hair loss.
The goal is to use the lowest effective dose to minimize potential side effects, a general principle in pharmaceutical treatments.

3. 1999 Study on Finasteride Doses and DHT Levels:

A 1999 study examined the effects of varying finasteride doses (0.01mg to 5mg) on serum and scalp DHT levels in men with androgenetic alopecia.
Doses of at least 0.2mg daily significantly lowered both serum and scalp DHT.
0.05mg daily lowered scalp DHT but had less effect on serum DHT.
5mg (Proscar dose) showed no significant difference in DHT reduction compared to 1mg (Propecia dose).
The study suggested that scalp DHT is more critical than serum DHT for hair loss treatment.

4. 1999 Study on Finasteride Doses and Hair Growth:

A double-blind, placebo-controlled study investigated the impact of finasteride doses (0.01mg, 0.2mg, 1mg, 5mg) on hair growth in men with Norwood 3 or 4 androgenetic alopecia.
Each group had over 100 subjects, followed for 6-12 months.
Measurements included hair counts via phototrichograms, patient/investigator assessments, and global photographic assessments.

5. Hair Count Results:

0.01mg was ineffective, showing no difference from placebo.
0.2mg increased hair counts, averaging 65 new hairs per square inch after 12 months.
1mg increased hair counts by 85 hairs per square inch after 12 months, slightly better than 0.2mg.
5mg showed slightly better hair growth than 1mg, but the difference (8 hair count difference) was not statistically significant.
"The only dose that didn't increase hair counts was the 0.01 milligram dose which was no different from placebo."

6. Subjective and Objective Assessments:

Patient self-assessments, investigator assessments, and global photographic assessments mirrored the hair count results.
5mg and 1mg were equally effective, 0.2mg was slightly less effective, and 0.01mg was ineffective.

7. DHT Suppression and Testosterone Increase:

0.01mg suppressed serum DHT by 11% despite being ineffective for hair growth.
0.2mg suppressed serum DHT by 61%.
1mg and 5mg both suppressed serum DHT by 68%.
All doses above 0.2mg led to an 18-19% increase in testosterone due to 5-AR enzyme inhibition.

8. Aromatization Speculation:

The video speculates on the potential for increased estrogen levels due to aromatization of the increased testosterone, possibly contributing to sexual side effects in some individuals.
However, the increase in testosterone is similar between 0.2mg and 1mg, yet side effects may differ, suggesting other unknown mechanisms.

9. Personal Finasteride Use:

The speaker uses generic 5mg Proscar tablets, quartering them into approximately 1.25mg doses for cost-effectiveness.
The speaker reports no side effects with this dosage.

10. Finasteride Half-Life and Dosing Frequency:

Finasteride has a short half-life (several hours), but its DHT-suppressing effects last up to four days.
Every-other-day dosing (e.g., 0.25mg) may be effective for some individuals.
Clinical research provides general guidelines, but doctors should determine appropriate dose titration.

11. Importance of Medical Consultation:

The video strongly advises against seeking dosage advice from online forums.
Dosage should be determined by a qualified doctor who can assess individual needs and responses.

12. Key Takeaways on Finasteride Dosing:

No benefit to exceeding 1mg of finasteride daily for hair loss.
Minimum effective dose is likely 0.2mg daily, though lower doses might suppress scalp DHT.
Every-other-day dosing is potentially effective due to the drug's prolonged DHT-suppressing effects.
The study's sample size was insufficient to definitively assess the incidence of side effects across different dosages.

13. Side Effects and Dose Dependence:

The study found similar safety profiles across all tested doses, including placebo.
However, the video suggests that side effects may be dose-dependent, with a higher incidence at 5mg compared to 1mg.
Lowering the dose from 1mg to 0.2mg may mitigate side effects without significantly compromising efficacy.

14. Conclusion:

Finasteride allows for flexible dose titration to balance efficacy and side effects.
The optimal dosage should be determined in consultation with a doctor.
Lower doses can be effective, challenging the notion that the standard 1mg dose is always necessary.
Avoid relying on unverified information from online forums and prioritize professional medical advice.