Spironolactone vs. Finasteride for Female Hair Loss

If you’re struggling with female hair loss, it’s important to know that many treatments are geared toward men (even if they don’t necessarily say it). Furthermore, their ingredients may be better suited toward specific types of hair loss, like pattern baldness, stress-related hair loss, or other causes.

For hair loss that’s tied to your hormones, two of the most common ingredients used in treatment include spironolactone and finasteride. Today, I’m going to compare them side-by-side so you can see which one might be best for you. 

	Spironolactone	Finasteride
How it works	Blocks androgens (like testosterone and DHT)	Prevents testosterone from turning into DHT
Timeline	4–6 months	6–12 months or longer
Efficacy for women	High	Not as high and often requires higher doses
Best for	Women with FPHL	Postmenopausal women
Side effects	Menstrual irregularities, increased urination	Potential for causing birth defects

How Hormones Affect

Before comparing the two ingredients, you should first understand how hormones like dihydrotestosterone and estrogens regulate the hair growth cycle.

Dihydrotestosterone (DHT) is an androgen that actually contributes to body hair growth. However, too much DHT can make follicles shrink and cause the growth phase of hair to shorten, leading to thinner and shorter hair, and then eventually hair loss. Notably, your genetic makeup can influence how sensitive your follicles are to DHT.

Estrogen also plays a role in hormonal hair loss. Changes in estrogen levels during menopause or after childbirth, for example, can disrupt your hair growth cycle and lead to hair loss.

Other hormonal factors that contribute to female hair loss include thyroid problems, high cortisol levels, and high insulin levels, which can lead to increased androgen production.

How Spironolactone and Finasteride Work

Spironolactone is a diuretic that helps your kidneys produce more urine, removing water and salt from the body while retaining potassium. It’s also an androgen receptor antagonist, which means it blocks androgens like DHT and testosterone from binding to the receptors located in your hair follicles. In doing so, it reduces the amount of androgens both produced and received by your hair follicles. 

Finasteride, on the other hand, is a 5α-reductase inhibitor that instead prevents the conversion of testosterone into DHT, helping improve hair thickness and growth.

Spironolactone, sold under brands like Aldactone and CaroSpir, and finasteride, under brands like Proscar and Propecia, can both be administered either orally or topically (although oral tablets are more common with finasteride and topical solutions with spironolactone)

Timeline for Effectiveness

In general, women taking spironolactone for hormone-related hair loss will start to see results within five months, with the full effects taking upward of a year to manifest. Taking it alongside a treatment like minoxidil can increase the success rate and may improve results. 

Finasteride, however, can take six to 12 months to produce results — if not longer. While you can also take finasteride and minoxidil together, studies suggest that minoxidil is better paired with spironolactone.

Potential Side Effects

Finasteride’s potential side effects include nausea, hot flashes, depression, and headaches. There is also a serious risk of birth defects (especially in male children) if you take it while pregnant.

Spironolactone’s potential side effects include breast tenderness, increased urination, and dizziness. In certain cases, you might need to have your electrolyte levels checked regularly to avoid imbalance. 

Who Should and Shouldn’t Take Spironolactone and Finasteride

Spironolactone

Spironolactone is ideal for most women who have female pattern hair loss. However, given that it’s a potassium-sparing diuretic, it should be avoided by women who have high potassium levels or problems with kidney function. It should also be avoided by women who are pregnant or breastfeeding. 

Finasteride

Finasteride is generally best for postmenopausal women who won’t be as adversely affected by the potential side effects. It should especially be avoided by women who are pregnant or may become pregnant in the future, given the high risk of birth defects.

Cost

The cost of products based on either ingredient will depend on the potency and the method of administration you choose. 

It’s important to note that both products (whether oral or topical) require a prescription, which means the cost can also vary depending on your insurance provider.

Choosing the Right Ingredient for Female Hair Loss

When it comes to spironolactone vs. finasteride for female hair loss, both ingredients are effective. However, spironolactone is the more commonly used supplement, while finasteride is often avoided for safety purposes.

To get help choosing the right ingredient for your needs, you can contact a licensed provider like Happy Head, a prescription hair growth treatment provider that offers specialized formulas based on personalized DNA tests. Its options include spironolactone-based formulas designed specifically for female users, such as TopicalRx Solution: Spironolactone & Minoxidil for Women, which uses FDA-approved ingredients with the strongest topical DHT blocker. This way, you can better avoid the unwanted side effects of other products while still aiding in:

• Prevention: Keeping your hair strong
• Recession: Slowing down hair loss
• Thinning: Regrowing and strengthening hair
• Maintenance: Post-transplant hair growth

Happy Head also makes it easy to get a prescription: You start with a free online consultation administered by a board-certified dermatologist, who creates a treatment plan that’s tailored toward your hair and the severity of your needs. Once prescribed, your custom treatment can be delivered directly to your door without any in-person visits or complicated paperwork.

If you’re still unsure whether spironolactone or finasteride is better for you, working with a brand like Happy Head will likely be most effective for finding the right treatment.