Sexual side effects are a recognized risk of oral finasteride. Depression and suicidal thoughts or behavior also appear in FDA prescribing information, in the section covering reports received after approval. These findings come from different kinds of evidence and should not be folded into one risk percentage.[1]

What the trials measured

In the first year of the hair-loss trials summarized in the label, sexual side effects included lower libido, erectile difficulties and ejaculation problems. One or more of these events was reported by 3.8% of men receiving finasteride and 2.1% receiving placebo.[1]

Those are group results from specific trials. They help put the possibility into context, but they do not predict whether an individual will have a side effect. The label also cautions that trial rates may differ from rates in routine practice.[1]

What postmarketing reports add

The label includes reports of sexual dysfunction that continued after discontinuation, as well as depression and suicidal thoughts or behavior. Because they are voluntary and the size of the exposed population is uncertain, they cannot reliably establish how frequent those outcomes are or prove causation in every case.[1]

A scalp formulation does not remove every systemic concern. In 2025, the FDA warned about adverse events reported with compounded topical finasteride and noted that bloodstream absorption is expected. Compounded topical finasteride is not FDA approved.[2]

Making the decision less abstract

Before treatment, it is reasonable to describe what your mood and sexual function are like now, what concerns would change your decision, and how follow-up would work. A later change is easier to explain when there is a clear starting point.

During treatment, useful information includes the exact symptom, when it began, its effect on daily life and the product being used. The conversation should address both how much the hair benefit matters to you and whether the symptoms make the treatment unacceptable.

New depression or major mood changes warrant prompt attention. Suicidal thoughts need immediate support: in the United States, call or text 988; call 911 for an immediate life-threatening emergency.[3]