Finasteride can cause temporary changes in libido, erectile function, or ejaculation, most of which resolve after discontinuation. Persistent sexual side effects are rare, but patients experiencing lasting issues should discuss them with a healthcare professional.
Yes, finasteride typically reduces PSA by about 50 %. Doctors will adjust the PSA reading by doubling the measured value (or using a correction factor) to obtain a more accurate assessment of prostate health while on the medication.
Finasteride and topical minoxidil work via different mechanisms and are often combined safely. However, patients should verify with their prescriber that both products are appropriate for their specific condition.
Take the missed dose as soon as you remember, then continue with the regular once-daily schedule. Avoid taking two doses close together; choose a consistent time that fits your new routine.
Finasteride does not disqualify you from donating blood in Hong Kong, but you should inform the donation centre of any medications you are taking.
Finasteride is not approved for women because of the risk of birth-defects if a female patient becomes pregnant. Some clinicians prescribe it off-label for severe hirsutism, but this is done only under strict medical supervision.
Most men notice a reduction in hair loss within the first three months, while measurable regrowth often appears after 6-12 months of consistent use.
There are no known food interactions, but supplements that affect hormone levels (e.g., high-dose zinc, saw-palmetto) could theoretically alter finasteride’s effectiveness. Discuss all supplements with your pharmacist.
The 1 mg dose is approved for treating male-pattern hair loss, while the 5 mg dose is used for benign prostatic hyperplasia. Both contain the same active ingredient but are prescribed for different conditions and have distinct dosing guidelines.
Yes, as long as the cabinet remains cool, dry, and out of direct sunlight. Avoid storing the medication in humid environments like shower areas to preserve tablet integrity.
Finasteride is a prescription pill available in a 1 mg strength. It belongs to the Men’s Health category and works by modifying the activity of a hormone that contributes to hair loss and prostate growth. In Hong Kong, the Drug Office of the Department of Health classifies finasteride as a prescription-only medication. The active ingredient is marketed under brand names such as Propecia (1 mg for hair loss) and Proscar (5 mg for benign prostatic hyperplasia). This article covers finasteride, its pharmacology, approved and off-label uses, safety considerations, and practical guidance for patients.
Finasteride is a selective inhibitor of the enzyme 5-alpha-reductase. This enzyme converts testosterone into dihydrotestosterone (DHT), a potent androgen that shrinks hair follicles on the scalp and stimulates prostate cell growth. By blocking 5-alpha-reductase, finasteride lowers DHT levels in the blood and scalp by about 70 % - 80 %. The reduction in DHT slows or reverses the miniaturisation of hair follicles, helping to maintain hair density. In the prostate, lower DHT results in a modest reduction in gland size, which can alleviate urinary symptoms when higher doses are used. The drug is well absorbed after oral administration; peak plasma concentrations occur within 1-2 hours, and the half-life is roughly 5-6 days, allowing once-daily dosing.
Androgenetic alopecia (male-pattern hair loss) - The 1 mg dose is approved for treating thinning hair on the crown and vertex of the scalp in adult men. Clinical studies have shown that regular use can increase hair count and improve appearance after several months.
Benign prostatic hyperplasia (BPH) - Although the 5 mg formulation is the standard for BPH, the same active ingredient (finasteride) reduces prostate volume by inhibiting DHT-driven growth. In Hong Kong, BPH treatment is typically prescribed at the higher dose.
Finasteride is not approved for use in women or children. Its efficacy is based on large, peer-reviewed trials and regulatory assessments by agencies such as the US FDA and the European Medicines Agency (EMA). In Hong Kong, the Drug Office follows these international standards when evaluating the medication.
Female hirsutism (excess facial/body hair) - Small observational studies suggest that low-dose finasteride may reduce unwanted hair growth in women with hyperandrogenic conditions. This use is not approved by the Hong Kong Drug Office and requires careful supervision because finasteride can cause birth-defect risks.
Prostate cancer risk reduction - Some long-term trials have examined whether finasteride lowers the incidence of low-grade prostate cancer. While the overall risk of developing prostate cancer may be reduced, there is a reported increase in detection of higher-grade cancers, leading regulatory agencies to caution against routine use for cancer prevention. Off-label use for this purpose must be discussed with an oncologist and a urologist.
Disclaimer: Off-label use requires medical supervision and individualized risk assessment.
Practical tip: Always inform your prescriber of every medication, supplement, or herbal product you are taking.
This article provides educational information about finasteride and is not a substitute for professional medical advice. Treatment decisions, including use for unapproved indications, must be made under the guidance of a qualified healthcare provider. The content is intended for informational purposes and does not constitute medical recommendations. Always consult a physician before starting, stopping, or changing any medication regimen.
