If you’re a man looking to find practical treatment options for hair loss, you’ve no doubt heard of finasteride. In fact, that’s probably why you’re here.
Finasteride is the active ingredient Propecia® and is one of the most popular and effective hair loss medications available today. It’s also one of only two treatments for male pattern baldness approved by the FDA.
That’s because it works. Used on its own, finasteride has been shown to stop hair loss and even improve hair growth in the majority of men who use it, often within three to four months.
Finasteride comes in both oral and topical forms and is designed for use one time per day. It’s easy to use and, under the supervision of a healthcare professional, can stop male pattern baldness in its tracks without the need for costly cosmetic procedures or hair pieces.
However, like other medications, finasteride comes with its own risks.
There are also a lot of misleading finasteride warnings, which is why it's important to get the facts right before you start using it yourself.
In general, the risk of side effects from oral finasteride is low. Research shows the vast majority of men who use finasteride over the long term benefit from a successful hair loss treatment with few or no undesired results.
Low sex drive, erectile dysfunction, and ejaculation issues are a few of the known finasteride sexual side effects.
Best practice to prevent side effects includes following the prescribed dosage, taking the medicine at the same time every day, or taking a lower dosage, all of which should be done with the guidance of a healthcare professional who can help you safely take a lower dose.
If you’ve tried to avoid the side effects of finasteride and they persist, talk to your healthcare provider about other options.
Oral finasteride is a prescription medication that treats male pattern hair loss by reducing levels of dihydrotestosterone (DHT), a hormone that shrinks hair follicles.
Finasteride works by inhibiting an enzyme called 5-alpha-reductase, which converts part of your body’s testosterone into dihydrotestosterone, or DHT, the primary culprit behind male pattern baldness.
This form of hair loss develops gradually due to the effects of DHT on the hair follicle (read our complete guide on DHT and hair loss to learn more about this process).
Reducing DHT levels protects your hair follicles from miniaturization, preventing male pattern baldness from becoming worse while stimulating re-growth in some patients.
Most men tolerate oral finasteride well, but some may experience mild sexual side effects.
Common Propecia side effects (1mg finasteride) include:
Erectile dysfunction (ED)
Decreased libido
Ejaculation disorder
Side effects are more common with the higher-dose 5mg finasteride that’s used to treat BPH or benign prostatic hyperplasia.
In addition to the above side effects, Proscar has two additional listed side effects:
Breast enlargement and/or tenderness (sometimes called gynecomastia)
Skin rash
Read more about finasteride and its side effects.
Like oral finasteride, topical finasteride works by reducing levels of DHT. In one study, researchers found that topical finasteride is just as effective as oral finasteride for treating hair loss.
Possible side effects of topical finasteride include:
Skin irritation
Sexual side effects, like reduced libido
Psychological side effects, like mood changes
Risk of exposure to others (especially pregnant people)
We offer topical finasteride in our topical finasteride & minoxidil spray, which you can apply directly to your scalp to promote hair growth and prevent hair loss from worsening.
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Side effects are a risk of using almost all medications. However, using finasteride the right way may reduce your likelihood.
Consider the following tips to use finasteride safely.
Finasteride is prescribed at a dosage of 1mg per day to treat male pattern baldness. There’s no need to take a higher dose than this, as it won’t improve your results. Using finasteride at a higher dosage may actually increase your risk of side effects.
Finasteride typically works best when it’s taken at approximately the same time every day. You can use finasteride with or without food.
Learn more about the best time to take finasteride in our guide (spoiler alert: it doesn’t really matter when, as long as you’re consistent).
If you forget to take finasteride, skip the missed dose and continue your regular dosing schedule the next day. Do not take more than one dose of finasteride at a time.
Store finasteride at room temperature inside its original container. Information from the FDA notes that finasteride should be stored below 30°C (86°F), protected from light, and tightly closed.
Avoid storing finasteride in the bathroom or other spaces with heat or excessive moisture
In certain cases, side effects are a temporary annoyance. Make sure to inform your healthcare provider so that they can track your progress and, if necessary, alter your dosage
Oral finasteride generally doesn’t cause interactions with other drugs. However, it’s still important to tell your healthcare provider about any other medications you use or medical conditions you may have.
Wondering how to take finasteride for hair loss without side effects? There’s no 100 percent guarantee that you can totally avoid the side effects of finasteride, but here are some important things to remember:
Oral finasteride is clinically proven to treat male pattern baldness but may cause mild sexual side effects in some men.
These side effects are rare, usually temporary, and often improve with time or dose adjustments.
Following your prescribed dose, staying consistent, and considering topical options can help reduce side effects.
If side effects persist, speak to your provider. They can help you adjust your dose, or discuss whether it might be time to try something else.
We offer both oral and topical finasteride online, including in our Hair Power Pack.
You can also explore other options in our complete range of hair loss treatments. If you’re interested in using finasteride, learn more about what to expect in our guide to the typical finasteride results timeline.
Want to get started with hair loss treatment? Take our free quiz to explore your best options, including oral and topical finasteride.
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This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.