One of the most common questions many men have about finasteride is, "What will happen if I stop taking the drug?" They wonder if the hair loss prevention effects are permanent, or will their hair begin to thin and fall out again?
Finasteride works by stopping the conversion of testosterone to dihydrotestosterone (DHT), the male sex hormone responsible for baldness. Studies show that 1mg of finasteride taken daily decreases DHT levels on the scalp by about 65 to 75 percent — enough to significantly slow or even stop hair loss in most men.
DHT-blocking drugs like finasteride belong to a category of medications known as 5α-reductase inhibitors, or 5-ARIs. Our guide to DHT and male hair loss covers in more detail how finasteride works for hair loss prevention.
Because finasteride works by blocking the specific enzyme responsible for DHT, it only prevents hair loss while the drug is active in your body. Once you stop taking finasteride, your body starts to convert testosterone to DHT again and your hair follicles start to react as they normally would.
In this guide, we’ll cover what you can expect to happen if you stop taking finasteride, as well as the long-term effects that stopping finasteride can have on your hairline, thickness and all-round hair health.
Finasteride has a half-life of around five to six hours in men 18 to 60 years of age (and eight hours in men over the age of 70), meaning it needs to be taken daily in order to be effective. Once you stop taking finasteride, the dose of the medication that’s active in your body will slowly decline until it’s completely excreted over the course of several days.
When there’s no longer any finasteride in your body, the 5α-reductase enzyme will no longer be blocked, meaning your body will once again start to convert a small percentage of testosterone into DHT.
If you’re genetically prone to male pattern baldness, this can mean that the DHT will once again start to affect your hair follicles, resulting in thinning of the hair on your scalp, hairline recession and other male pattern baldness effects.
In short, if you stop taking finasteride daily, you’ll lose the hair you’ve gained in about one year. Finasteride isn’t a lifetime cure — instead, it’s a treatment that you need to keep taking if you want to continue to stop hair loss.
Since finasteride only prevents hair loss while it’s active in your body, you’ll need to use it daily over the long term if your goal is to stop baldness and keep as much of your hair as possible.
For many men, this means taking finasteride for years. Currently, studies show that finasteride is safe to use over the long term. For example, the Prostate Cancer Prevention Trial study of almost 19,000 men who had taken finasteride for seven years concluded that there is “little need to worry” about any long-term consequences from finasteride.
Other long-term studies of finasteride show similar results, with a 1mg dose of finasteride well tolerated over a period of five years.
Like most prescription medications, finasteride comes with a risk of side effects.
Of these side effects, sexual dysfunction is the most common reported by men taking finasteride. In clinical trials, 1.3 percent of men experienced some form of erectile dysfunction, 1.8 percent experienced a decrease in libido and 1.2 percent experienced a decrease in overall ejaculate level.
A very small number of men (less than one percent) also experienced breast tenderness and rashes, too.
While the vast majority of men who experience side effects from finasteride also notice these side effects stop when they stop using the medication, there have been reports that a small number of men continue to experience side effects after they stop taking the medication. It’s also worth noting that this area of research regarding finasteride side effects is ongoing.
In short, once you stop taking finasteride, you can expect that the hair you’ve preserved will start to fall out, just like it did before you took the medication. Finasteride only works while the drug is active in your body, meaning you’ll go back to a normal rate of hair loss once it’s excreted.
If you’ve experienced side effects from finasteride — including sexual dysfunction, breast tenderness and rashes — in most cases, they will stop once you stop taking it. This is documented in most studies of finasteride’s side effect profile. However, it’s important that you are aware of the potential long term side effects of finasteride before you start taking it. And definitely talk to your doctor if you experience side effects while on finasteride or are concerned about experiencing side effects.