Hair loss can be an emotionally challenging experience, and the quest for a foolproof remedy is understandable.

Hormonal imbalances, certain medical conditions, and even stress can contribute to hair loss—scientifically known as alopecia. Androgenetic alopecia (AGA) is a common occurrence in men and women, and the etiologic factors in this condition involve the enzyme 5-α (alpha)-reductase. When it comes to treatment, one option that has gained significant attention is finasteride.

In order to understand the mechanism of action of finasteride, let’s recap the growth cycle of hair.

Hair Growth Cycle

As discussed in our previous blog post, human hair grows in four stages:

1. Anagen

2. Catagen

3. Telogen

4. Exogen

In androgenetic alopecia, the hair cycle is altered: the duration of the anagen phase is reduced while that of the telogen phase is prolonged, resulting in shorter hairs and eventual balding.


What is Finasteride?


Finasteride, also known by the brand name Propecia, is an approved medication used primarily for the treatment of male pattern baldness. It belongs to a class of drugs known as 5-α reductase inhibitors (5-ARIs).

In 1992, oral finasteride (5mg/day) was approved for the treatment of benign prostatic hyperplasia. Its anti-androgen properties resulted in the drug also being considered for treating AGA. In 1997, topical finasteride was evaluated with a placebo‐controlled trial involving 52 participants with promising results for hair regrowth and reduction of balding without major side effects reported.

Oral finasteride has been extensively studied for the management of androgenetic alopecia. According to systematic reviews, using oral finasteride daily increases hair count while also improving the patient and investigator’s assessment of hair appearance.

Long-term use for up to five years has been shown to decrease the likelihood of developing further visible hair loss. A study of 270 men with high levels of serum 5 alpha-dihydrotestosterone showed that starting oral finasteride in younger patients had a better response rate.


How Finasteride Works to Combat Hair Loss


Finasteride inhibits a specific enzyme in the body that converts testosterone into dihydrotestosterone (DHT), the hormone primarily responsible for male pattern baldness. DHT wreaks havoc on hair follicles, leading to their miniaturization and eventual death.

By reducing DHT levels in the blood and the scalp, finasteride slows down hair loss, prevents further thinning of hair, and in some cases, stimulates hair regrowth.

Topical finasteride is thought to enhance hair density and reduce further hair loss by lowering DHT levels locally around the hair follicle, which could help to slow the follicular shrinking that underpins this form of hair loss.

According to a study published in the International Journal Of Clinical Pharmacology and Therapeutics, over the course of one week of treatment, scalp DHT was reduced by 68% to 75% with topical finasteride and from 62 %to 72% with oral finasteride for men with androgenetic alopecia.

For many individuals, finasteride has been a game-changer, effectively halting hair loss and even fostering new hair growth. One of the major benefits of using oral finasteride for alopecia is convenience: as it is an oral medication that can be taken once daily, it makes it a relatively hassle-free option for those incorporating it into their daily routines. Both the pill and topical gel also offer a non-invasive alternative to more extreme measures like hair transplants or wigs, allowing individuals to regain their confidence without going under the knife.


Finasteride Formulations


Finasteride is available in two forms: as an oral tablet and as a topical gel/ solution. While oral tablets are commonly prescribed, some find the topical solution more convenient.

Oral Finasteride

Adult dosage: 1 mg tablet per day.

Take the medication once a day with a full glass of water, with or without meals.

The drug may not provide you with the full benefit for up to 3 months or longer. For the most optimal outcomes, use finasteride on a regular basis.

Your doctor needs to monitor your progress while you’re taking finasteride. To screen for prostate cancer, you will need to have regular prostate specific antigen (PSA) testing.

Topical finasteride

Adult dosage: usually once daily

Using your fingers or a dropper, apply the product straight to the scalp. Apply it evenly using your palm or the dropper, making sure to completely cover the regions affected by hair loss.

You may need to apply it once or twice a day, depending on the formula. To confirm, read the instructions on the packet. For optimal benefits of topical finasteride, you must remember to apply it every day.

Some men see thicker hair after only a few months, although it generally takes at least four months to begin regrowing your hair. After 9 to 12 months of application, you should see an improvement.

Finasteride Side Effects


Studies have shown that over 90% of finasteride users report either no side effects or very mild ones that do not hinder their quality of life.

Oral finasteride: The sexual side effects of oral finasteride are of notable concern and include decreased libido, erectile dysfunction, decreased ejaculate volume, and breast tenderness or enlargement.

While these side effects are reported in a small percentage of individuals, they can be distressing for those who experience them. Another important point to consider is that finasteride must be taken continuously to maintain its effects. Once you stop taking the medication, any benefits gained may gradually diminish, and hair loss may resume. Reliance on finasteride as a long-term solution is necessary.

There have also been reports of more severe side effects associated with finasteride, such as depression, anxiety, and even suicidal thoughts. The link between finasteride and these mental health issues is still being studied.

Topical finasteride: While considered a safer alternative to the oral form, topical finasteride has demonstrated some side effects in studies. Potential side effects include skin erythema/ irritation and contact dermatitis, increased liver enzymes, nocturnal enuresis, testicular pain, headaches, and oropharyngeal pain.

Precautions to take while using finasteride


  • Consult a medical professional before starting any new medication. They can assess your situation and determine if finasteride is right for you.
  • Women or children should never use finasteride.
  • Do not use finasteride if you are allergic to it.
  • Finasteride use may increase your chances of acquiring a severe form of prostate cancer. Consult with your healthcare provider about this risk.
  • Inform your doctor if you have a history of prostate cancer, liver illness, or abnormal liver function tests.
  • If you miss a dose, use your next dose at the regular time. Never take two doses at the same time.
  • If a woman is exposed to finasteride while pregnant, it can result in birth abnormalities. A woman who is pregnant or may become pregnant should not handle a broken finasteride pill since the medicine may be absorbed through the skin.
  • If a woman comes into contact with a broken or crushed tablet, she should immediately wash the area with soap and water.
  • It is crucial to follow the prescribed dosage and usage instructions. Many people either take too much or not consistently, which can hinder the treatment’s effectiveness.

Tips for Maximizing the Effectiveness of Finasteride Treatment


Hair regrowth is gradual and may take several months before significant improvement is noticed. In addition to finasteride, adopt a healthy lifestyle. This includes a balanced diet, regular exercise, and minimizing stress.  A healthy lifestyle supports hair growth and overall well-being.

Remember to take care of your hair and scalp. Use gentle shampoos and conditioners, avoiding harsh chemicals or excessive heat styling.

It is also essential not to overlook the importance of addressing the underlying causes of hair loss, such as stress, diet, and genetics, in combination with any chosen treatment.



The opinions shared in this article belong to the author and, like all content on Gambit’s Health Hub, should not be considered a replacement for professional medical advice, diagnosis, or treatment. If you have any health-related inquiries, consult with your preferred healthcare professional or visit a licensed, Canadian physician through Get Gambit for a supported condition.

This article has been medically reviewed by:

Dr. Taneer Ahmed, MBBS, MS

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