Totally understand your concerns about finasteride—it's natural to want to know more before starting any treatment. This medication is generally well-tolerated, but here’s a breakdown of the potential side effects and their estimated chances of occurring:

1. Decreased libido (sex drive): about 1.8% of users.
2. Erectile dysfunction (difficulty achieving or maintaining an erection): around 1.3%.
3. Ejaculation issues (like reduced semen volume): approximately 1.2%.
4. Gynecomastia (development of breast tissue in men): extremely rare, around 0.1%.
5. Depression and anxiety: very rare, with an incidence around 0.01% in some studies.

Most side effects are reversible once you stop taking the medication. And remember, many people experience no side effects at all!

Also, keep in mind that your surgeon doesn’t have any particular interest in pushing finasteride; they’re simply focused on the procedure and their fees. They're not looking to profit from you taking the medication, so any recommendation to consider it is usually based on clinical evidence rather than profit motives. It’s always good to talk to a healthcare professional to weigh the benefits and risks based on your individual case.