Article / Finasteride: why does the hereditary-hair-loss drug cause sexual side effects? If you want to avoid them, what alternatives can you use?

Finasteride: why does the hereditary-hair-loss drug cause sexual side effects? If you want to avoid them, what alternatives can you use?

Genetic hair loss is the leading cause of thinning and baldness in both men and women, driven by DHT's effect on the follicle. One common medical treatment is Finasteride.

What is genetic hair loss?

Genetic hair loss, or androgenetic alopecia, is an inherited form of hair loss combined with the effect of sex hormones — especially dihydrotestosterone (DHT). DHT gradually shrinks follicles, shortens the hair cycle, and produces progressively thinner regrowth until follicles close entirely, leaving visible scalp.

Can genetic hair loss be prevented?

Hereditary hair loss is not a contagious disease, but rather a slow and continuous deterioration process of the hair roots. Hereditary hair loss can be partially prevented — it is not possible to prevent hereditary hair loss 100%, as it is primarily caused by genetics and hormones. However, understanding the mechanism of hereditary hair loss and starting to care for it from the early stages will help slow the development of hereditary hair loss and reduce its severity.

What does genetic hair loss look like?

Pattern of genetic hair loss in men

M-shaped recession at the hairline
Thinning at the crown
In severe stages, only the sides and back of the head remain

Pattern of genetic hair loss in women

A wide thin patch along the central part
Overall thinning but rarely full bald patches
Usually becomes noticeable after age 30

Modern medical treatments for genetic hair loss

Modern medical care focuses on suppressing DHT and extending follicle lifespan with two main drugs:

1) Finasteride

directly suppresses DHT production. It's the main drug for genetic hair loss in men and helps reduce genetic shedding.

Finasteride is currently available in two forms: oral (Oral Finasteride) and topical (Topical Finasteride). The oral form is used only in men — pregnant women or those who suspect they may be pregnant must not handle this medication, and a doctor should be consulted before stopping the medication. The topical form is suitable for those with mild to moderate hereditary hair loss; it is applied by gently massaging into the scalp without rinsing, once per day. Avoid shampooing for at least 4–6 hours after application. Results will begin to show with continuous use over 3–6 months.

2) Minoxidil

stimulates blood flow and extends the growth phase. Suitable for both men and women, it doesn't reduce genetic shedding directly — instead it thickens hair and stimulates new growth.

What is Finasteride, and why does it reduce genetic hair loss?

Finasteride belongs to the 5α-reductase inhibitor class. It blocks the 5α-reductase enzyme that converts testosterone into DHT — the hormone that shrinks follicles. With less DHT, follicles aren't damaged and stay healthy longer, so hair fall is reduced.

How to use: 1 mg per day. To treat hair loss, take continuously for at least 3–6 months before results appear. If you stop, DHT rises again and hair fall can return within 3–6 months.

Finasteride reduces genetic hair fall and preserves existing hair, but does not regrow hair that has already been lost.

Who is Finasteride best for?

It suits men with hair fall, thinning at the crown, or a receding M-shaped hairline — classic signs of male-pattern genetic hair loss.
For those who want to slow hereditary hair loss more than stimulate new hair growth — because Finasteride helps reduce hair fall but does not help hair regrow.
For those who can use the medication continuously — because Finasteride must be used continuously to see results in reducing hereditary hair loss.

Can women use Finasteride?

Women can use Finasteride in some cases, but Finasteride is not the standard first-line treatment option for hair loss in women — because results are not clearly established, and hair loss in women has many more causes than just hereditary hair loss. The standard medication that doctors currently tend to prescribe for female patients with hair loss is Minoxidil.

Doctors will recommend that women use Finasteride for treatment only when other treatment methods have not been effective, or when hereditary hair loss is clearly evident — and it must be under medical supervision in all cases. Women who are absolutely prohibited from using Finasteride — whether oral or topical — include pregnant women or those with a chance of becoming pregnant, and women who are breastfeeding.

Side effects of Finasteride for hereditary hair loss

Although Finasteride is highly effective, it may cause side effects in some people — particularly hormonal side effects, including:

Reduced sexual desire
Reduced sexual performance
Decreased semen volume
Mood swings or depression

These symptoms are often found in some users of Finasteride and usually improve when the medication is stopped. However, Finasteride should be used under medical advice and avoided in pregnant women or those planning to become pregnant.

Why does the hereditary hair loss medication Finasteride reduce sexual performance?

Finasteride reduces hereditary hair loss by inhibiting the enzyme 5-alpha reductase, which converts the hormone Testosterone → DHT (Dihydrotestosterone). Although DHT is the main culprit behind hereditary hair loss, DHT also plays a role in the reproductive system and male sexual function — DHT is involved in sexual desire, erection, and prostate function.

Lowering DHT levels with a drug like Finasteride can therefore help slow hereditary hair loss. However, when DHT is suppressed to a low level in some patients with hereditary hair loss problems — in addition to hair fall stopping, sexual performance also decreases. This is why it is necessary to carefully consider using this medication under medical advice.

If I stop Finasteride, will hair loss return?

Finasteride works by inhibiting the production of the hormone DHT, which is the main cause of hereditary hair loss. When the medication is stopped, DHT levels return to normal, causing hair roots to shrink again according to the same mechanism — and hair will begin to fall out within 1–3 months after stopping.

AloEx extracts with test results benchmarked against Finasteride

For those who are concerned about the side effects of Finasteride but still want to address hereditary hair loss, thinning, and baldness with a method backed by test results, I recommend getting to know 2 AloEx herbal extracts called AloEx Hydrosol Complex Extract and AloEx Phenolic Complex Extract, which have been tested by the Thailand Institute of Scientific and Technological Research (TISTR) and confirmed to have an efficiency of 89.50% in reducing hereditary hair loss compared to Finasteride, and 87.91% efficiency in promoting new hair growth compared to Minoxidil.

The AloEx Hydrosol Complex Extract and AloEx Phenolic Complex Extract are herbal extracts that are the main ingredients of AloEx products, formulated from traditional Thai herbal medicine recipes that have long been used to address hair loss and restore healthy new hair growth. Using just 1 AloEx product is equivalent to nourishing and restoring hair and scalp from 2 angles — from reducing hair fall similar to Finasteride, to stimulating new hair growth similar to Minoxidil — without any concerns about side effects.

Other natural extracts for reducing hereditary hair loss as alternatives to Finasteride

In addition to the natural extracts prepared using the proprietary method of the AloEx brand, there are also other natural extracts used as ingredients in hair loss products on the market. AloEx also uses other extracts to supplement the anti-hereditary-hair-loss function in AloEx products — such as Saw Palmetto, Procapil™, and Capixyl™.

Other natural extracts commonly used in hair loss products currently on the market

Saw Palmetto – Inhibits the enzyme 5-alpha reductase, preventing the conversion of Testosterone to DHT.
Procapil™ – Contains Oleanolic Acid that helps inhibit the enzyme 5-alpha reductase.
Capixyl™ – Rich in Biochanin A, which acts as a DHT Blocker.
EGCG from green tea – reduces the activity of the enzyme 5-alpha reductase.
Caffeine – helps reduce the impact of DHT on hair roots.
Baicapil™ – helps reduce the impact of DHT on hair roots.

Shop AloEx products as an alternative to Finasteride.

AloEx Everyday Organic Conditioner – Organic Herbal Conditioner for Hair Loss Reduction

Organic Herbal Hair Conditioner - Reduces hair breakage and loss - Adds softness and volume - Floral Sunshine scent - Suitable for all hair types and scalp conditions - Safe for daily use - Revitalizes dry, damaged hair, restoring softness and shine

AloEx Everyday Organic Shampoo – Organic Herbal Shampoo for Hair Loss Reduction

Organic Herbal Shampoo: Revitalize dry, damaged hair, restoring it to soft, smooth, and manageable locks. Enhances hair softness and moisture, with a floral sunshine fragrance. Suitable for all hair types and scalp conditions. Safe for daily use.

AloEx Cute Eyebrow Nourishing Cream – Eyebrow Nourishing Cream

Eyebrow Nourishing Cream A rich, nourishing cream with a lightweight, fast-absorbing texture that leaves no sticky residue. Enriched with natural extracts, it helps strengthen eyebrow and hair health, reduces breakage and shedding, and stimulates the growth of healthy new hair.

AloEx Organic Intensive Hair Serum helps nourish hair to appear thicker and darker naturally.

This organic serum is designed for individuals experiencing hair loss. It nourishes the hair and scalp, strengthening them and promoting thicker, darker hair. It effectively reduces gray hair.

AloEx Natural Hair Mask – Silicone-Free Hair Treatment Mask

This scalp and hair treatment nourishes the scalp and hair, strengthening them and reducing the likelihood of hair loss, thinning, and damage. It contains concentrated herbal extracts.

AloEx Extra Mild Shampoo – Shampoo for Hair Loss Problems, Gentle Formula

This gentle shampoo is formulated for individuals with hair loss concerns and sensitive skin prone to irritation and chemical sensitivity. It effectively cleanses away dirt and chemical residues while revitalizing the scalp and strengthening hair with concentrated herbal extracts.

AloEx Black Shampoo – Shampoo for Hair Loss, with Black Sticky Rice Formula

This shampoo is designed for individuals experiencing hair loss. It is suitable for dry scalp and hair and helps cleanse impurities and chemical residues while restoring moisture. Enriched with concentrated herbal extracts, it leaves hair strong, soft, and smooth.

References

Irwig, M. S. (2011). Persistent sexual side effects of finasteride for male pattern hair loss. Journal of Sexual Medicine. https://pubmed.ncbi.nlm.nih.gov/21418145/

StatPearls Publishing. “Finasteride.” StatPearls, 2024. https://doi.org/10.1016/j.supflu.2011.07.017

Food and Drug Administration (FDA Thailand). "FDA Reminds Patients Before Using Finasteride: Sexual and Psychiatric Side Effects." HFocus. https://www.hfocus.org/content/2018/09/16278

Faculty of Medicine Siriraj Hospital, Mahidol University. Finasteride Drug Information Leaflet: Precautions and Side Effects. https://www.si.mahidol.ac.th/th/division/hph/admin/download_files/154_49_183Oc2Q.pdf