« Back to Blog

Propecia (Finasteride) Side Effects to Look Out For

Are you struggling with hair loss? You're not alone. There are millions worldwide with male pattern baldness who are also looking for solutions to hair loss. You've probably heard about Propecia but are worried about its potential side effects.

Join me as we dive deeper into the science behind Propecia and discover the side effects you need to look out for.

What is Propecia?

Propecia, or Finasteride, is an oral prescription drug for treating male pattern baldness. It works by stopping the conversion of testosterone into DHT or dihydrotestosterone, a hormone that impacts male pattern hair loss.

By lowering DHT levels, Propecia can help slow hair loss and promote hair growth.

Propecia is also prescribed for men with an enlarged prostate or benign prostatic hyperplasia.

Propecia is also available in a topical solution, but the FDA doesn't approve it since it lacks the clinical trials needed.

Merck and Co. sell finasteride tablets under the brand name Proscar.

The Science Behind Propecia

Propecia contains the drug finasteride, which belongs to a class of medications known as 5-alpha reductase inhibitors. Finasteride works by blocking an enzyme that reduces testosterone conversion to dihydrotestosterone. DHT is the main culprit behind male pattern baldness. Once DHTs are reduced, it slows down male pattern hair loss; in some cases, patients experience hair growth.

Several studies prove that Propecia works. In one study, 1,553 males with pattern hair loss were given oral finasteride therapy for two years and saw significant results. Another recent study shows that 80% of 450 men with pattern hair loss who took propecia showed improvement in 12 months.

Common Side Effects of Finasteride Tablets

man experiencing ED looking beneath the sheets

Persistent diminished libido

Decreased libido is a persistent sexual side effect of finasteride users. A 2011 study published in the Journal of Sexual Medicine showed a decreased interest in sex among Propecia users.

Erectile dysfunction

photo of a man with a banana hanging out of his zipper pointing downward

Erectile dysfunction is also part of persistent sexual side effects for finasteride users. A study made by Northwestern University shows that out of 11,909 men who took Finasteride, those with the most prolonged exposure to the drug were more likely to develop ED than those who took them for shorter times.

Finasteride users also experience several ejaculatory disorders ranging from premature, delayed, and complete inability to ejaculate.

Suicidal thoughts

man experiencing depression

Since sexual dysfunction is a common side effect of Propecia, more men get depressed and even have suicidal thoughts. A 2012 study in the Journal of Clinical Psychiatry showed that 44% of former finasteride users experienced suicidal thoughts versus 3% of men who never used Propecia.

Finasteride Shedding

Some finasteride users may notice increased hair shedding during the first few months of treating male pattern baldness. This is a normal part of the hair cycle, where thinner hair makes way for newer and thicker hair growth.

Mild common side effects usually subside within a few days or a week. If they're severe or don't disappear, consult your healthcare professional.

Less common side effects of finasteride therapy

  • Pain in testicles

  • Unusual weight gain

  • Depression

  • Nipple discharge

  • Breast pain

  • Breast tenderness

  • Decreased amount of semen

  • Back pain

  • Diarrhea

  • Headache

  • Stomach pain

  • Dizziness

Is Propecia Safe To Use?

Generally, yes, Propecia is safe to use. It's one of two treatments for male pattern baldness that the FDA approves, the other being Rogaine (minoxidil).

If you're taking Finasteride to treat hair loss or BPH, you need to be aware of these important warnings:

Avoid contact with pregnant women

Pregnant women should not handle crushed or broken finasteride tablets. Skin contact may lead to defective male fetuses. Call your healthcare professional if skin contact with Finasteride occurred with a pregnant woman.

Prostate Cancer Warning

Propecia may increase the risk of a faster-growing form of prostate cancer. Remember that the drug is also used for enlarged prostrates and can decrease your PSA or prostate-specific antigen. If you notice a high level of this antigen while taking Finasteride, it could be a sign of prostate cancer. Consult your healthcare professional if you plan to take Finasteride.

Liver Disease Warning

If you have liver disease, your body may process this drug more slowly, which can increase the risk of side effects. Your healthcare professional may give you low-dose Finasteride.

How To Use Finasteride Safely?

Your dose and form of taking Finasteride may vary and will depend on :

  • Age

  • Condition being treated

  • Severity of condition

  • Other medical conditions

  • Reaction to the initial dose

It's crucial to take Finasteride as prescribed. If you take too much, you may experience adverse reactions like a skin rash, breast tenderness, decreased libido, ejaculation disorder, and sexual intercourse inability.

If you miss a dose, don't take an extra dose to make up for the one you missed. Take the next dosage as usual. Larger doses won't improve results and may increase the risk of side effects.

If you're taking Finasteride for benign prostatic hyperplasia, you may experience an improvement in your condition, like improved urine flow and a lesser urge to urinate. On the other hand, if you're taking Finasteride for hair regrowth, you may notice slower hair loss than before.

Additional reminders when taking Finasteride:

  • No crushing, cutting, or chewing of tablets

  • Store finasteride at room temperature, preferably between 59 F and 86 F

  • Keep away from sunlight and high temperatures

  • Store in a cool and dry place

  • Always carry your tablets with you when traveling

  • Always have the original prescription labeled container to show airport personnel

  • Don't leave tablets in your car's glove compartment

The Different Dosages of Finasteride

Finasteride is available in either 1 mg or 5 mg dose. You may think the larger dose is more potent and more effective in hair loss treatment. This is not the case. Remember, Finasteride's other medical use is to lower symptoms of an enlarged prostate gland or benign prostatic hyperplasia.

If you have an enlarged prostate, you'll get the 5 mg dose. To treat male pattern baldness, 1 mg tablets are usually prescribed.

Serious side effects of Finasteride: When to call your doctor immediately

man having difficulty breathing

Call your doctor immediately if you experience side effects like a severe allergic reaction to Propecia. Here are other serious symptoms you should look out for:

  • Depression

  • Swelling in your tongue, lips, throat, or face

  • Lumps of pain in your breast

  • Nipple discharge

  • Chills

  • Cold sweats

  • Confusion dizziness

  • Trouble breathing

  • Hives

man experiencing dizziness

Interactions With Other Medications

There are no listed drug interactions between Propecia and other medications. However, it's still better to inform your healthcare professional or doctor about any prescription, over-the-counter, herbal, or dietary supplements you're taking.

Personal Insights

When I started looking for solutions for my male pattern hair loss, I came across Rogaine and Propecia, but after learning about the possible adverse effects, I only considered natural hair growth solutions for treating my hair loss.

A full head of hair with a ton of side effects doesn't work for me. What's the use of having a full head of hair only to face severe problems like erectile dysfunction, depression, losing sexual function, and prostate cancer?

A hair loss treatment with tons of persistent sexual dysfunction side effects is not for me.

man experiencing ED looking at his organ beneath his jogging pants

However, if you have an enlarged prostate or benign prostatic hyperplasia, that's another story. Your doctor may prescribe Propecia to treat an enlarged prostate.

When I realized there was no cure for male pattern hair loss, I shaved my head.

I've been sporting the buzz cut for years and most recently started a closer shave with my Freebird FlexSeries electric shaver.

Head shaving has freed me from worrying about male pattern hair loss and the never-ending treatments that won't restore my hair fully.


bald and bearded man shaving his head with rotary shaver

Experiencing hair loss can be an overwhelming experience for many. The good news is that treatment options like Propecia can help prevent further hair loss or even restore what you've lost. Take note, though, of the potential sexual dysfunction side effects you may face.

However, keep in mind that not everyone will experience these side effects. Propecia can be taken safely by using it as directed. For patients with an enlarged prostate or benign prostatic hyperplasia, Propecia is one of the prescription drugs your doctor may recommend, so you may benefit from the hair growth as a bonus side effect aside from treating your enlarged prostate.

If the side effects are a red flag for you, you can always choose to go bald and shave your head like me.

For tips on how to shave your head, feel free to click on the link.

Frequently Asked Questions

How long do Propecia side effects last after stopping?

If you stop using Propecia, you might see a reversal of its adverse effects within one year. Remember, it's a gradual process; hair follicles don't grow overnight, so be patient. Some guys have reported that their libido and ejaculation disorder persisted even after they stopped the medical therapy.

How long do Finasteride side effects last?

It can be quite a mixed bag with the side effects of Propecia. They may last a few days or a few weeks. If you're worried or if they seem severe, visit your doctor immediately. Some men have shared that persistent sexual side effects can be permanent even after stopping taking Finasteride.

How common are Propecia side effects?

The bad news is that Propecia side effects are pretty common. While over 90% of men who take Propecia tablets notice improvement and 66% experience renewed hair growth, sexual dysfunction comes with good results.

What are the long-term side effects of Propecia?

Some men have shared that sexual dysfunction side effects are permanent. Some reported that erectile dysfunction continued even after stopping taking Finasteride.

Is Propecia worth it?

According to the American Academy of Dermatology, Propecia slows hair loss in 88% of men and causes new hair growth in 66%. The numbers show that the treatment works for hair loss. The only question is, do you value hair growth over the potential side effects of taking finasteride therapy?

Which is worse? Being bald or risking erectile dysfunction, decreased libido, enlarged prostate, ejaculation disorder, male breast cancer, skin rash, male infertility, and depression, to name a few side effects of taking Finasteride.

If you experience an allergic reaction to Propecia, it's better to stop the treatment immediately.

Does Propecia lower testosterone?

No, Propecia doesn't lower testosterone, but it decreases the level of DHT or dihydrotestosterone by 70%.

How do you reduce the side effects of Finasteride?

Here are a few ways to reduce the side effects of Propecia. Follow the prescribed dosage, consult a licensed healthcare professional before treatment, take a lower dosage, maintain a healthy weight, exercise, and eat a balanced diet.

Is it safe to take Finasteride daily?

Yes, Finasteride is safe for daily use. A 7-year study tested the long-term consumption of Finasteride and found no long-term severe consequences except for the potential side effects.

« Back to Blog