Saw palmetto vs. finasteride: Which is the best choice for treating hair loss? Both options combat androgenetic alopecia, but they differ in potency, delivery, and clinical support.
Finasteride prescription products have well-documented results in slowing hair loss and promoting regrowth, while saw palmetto is a natural supplement with milder effects and fewer systemic risks.
Understanding how they work, their benefits, and potential side effects can help you make an informed decision based on your dermatologist’s guidance.
How DHT Affects Hair Follicles
Dihydrotestosterone (DHT) is an androgen hormone formed when the enzyme 5-alpha reductase converts testosterone into a more potent form.
While DHT is important for normal male development, influencing traits such as prostate growth, facial hair, and body hair, it can negatively impact scalp follicles in those genetically predisposed to hair loss.
In these individuals, follicle receptors are highly sensitive to DHT, which causes the follicles to shrink, weaken, and produce progressively finer strands. Over time, this process, known as follicle miniaturization, can eventually halt new hair growth.
Men are generally more affected, often experiencing recession at the temples and thinning on the crown, while women typically notice diffuse thinning across the scalp.
High levels of DHT alone do not guarantee hair loss; rather, genetic susceptibility determines how strongly the follicles react. This explains why some people maintain thick hair despite elevated DHT levels, while others experience significant shedding.
How Finasteride Works
Finasteride is a prescription medication that targets the hormonal pathway responsible for androgenetic alopecia, or pattern hair loss. It works by inhibiting type II 5-alpha reductase, the enzyme that converts testosterone into dihydrotestosterone (DHT).
By lowering scalp and serum DHT levels, finasteride reduces the hormone’s impact on sensitive hair follicles. This helps interrupt the miniaturization process, allowing follicles to remain active and produce thicker, healthier strands for a longer period.
Many users start seeing results within 3 to 6 months, with continued improvement over the first year of treatment. Though oral finasteride is FDA-approved for male pattern baldness, its use in women is more limited and must be carefully evaluated by a dermatologist.
Oral vs. Topical Finasteride
Finasteride is available by prescription in both oral and topical forms, each working to reduce DHT but differing in delivery and systemic exposure.
Oral finasteride, taken as a pill typically in 1 mg strength, has been widely studied and consistently lowers circulating DHT levels by up to 70%. This makes it highly effective, but it also increases the risk of systemic side effects.
Topical finasteride is applied directly to the scalp to reduce DHT at the follicle level while limiting absorption into the bloodstream. Topical use may preserve hair benefits with fewer systemic effects, though evidence is still developing.
A dermatologist can help determine which form is more appropriate based on individual needs.
Possible Side Effects When Using Finasteride
While finasteride is effective, it can cause side effects in some individuals. The most widely discussed concerns are sexual side effects, including reduced libido, erectile dysfunction, or decreased ejaculate volume.
These occur in a small percentage of users and may resolve after discontinuation. Some men also report mood changes or breast tenderness, though these are less common.
With topical finasteride, systemic side effects appear less frequently but can still occur depending on absorption. Finasteride should not be handled by pregnant women, as it can affect fetal development.
Regular follow-up with a prescribing physician is important to monitor effectiveness, address concerns, and ensure the treatment remains safe.
Who Should Avoid Finasteride
Not everyone is an ideal candidate for finasteride. It should generally be avoided by women who are pregnant, planning pregnancy, or breastfeeding, due to the risk of birth defects.
Men with a history of significant adverse reactions to finasteride or related drugs should also refrain from use. Caution is advised for those with liver disease, as the drug is metabolized in the liver.
Additionally, finasteride is not effective for hair loss unrelated to DHT, such as alopecia areata or telogen effluvium, and may provide no benefit in these cases.
A dermatologist can help determine whether finasteride is an appropriate treatment option or if alternatives may be more effective and safer.
How Saw Palmetto Works
Saw palmetto is a plant extract derived from the berries of the Serenoa repens palm, and it is often promoted as a natural alternative for managing androgen-related hair loss.
Saw palmetto works by inhibiting 5-alpha reductase, the same enzyme targeted by finasteride, thereby reducing the conversion of testosterone into dihydrotestosterone (DHT).
By lowering DHT activity in the scalp by approximately 32%, saw palmetto may help slow follicle miniaturization and support healthier, thicker hair growth.
Unlike finasteride, which is prescription-based and well-studied, saw palmetto is typically available as a supplement or topical product with more variable concentrations.
While promising, its overall potency is milder, and results can differ significantly among users depending on dosage, formulation, and individual sensitivity to DHT.
Oral vs. Topical Saw Palmetto
Saw palmetto is available in both oral supplements and topical formulations. Oral forms, usually capsules or tablets, deliver the extract systemically, which may help lower DHT throughout the body but can also increase the likelihood of side effects.
Topical saw palmetto, applied directly to the scalp, is designed to target hair follicles more locally while limiting systemic absorption.
Some shampoos, serums, foams, and hair supplements include saw palmetto as a key ingredient, though concentrations and absorption rates can vary widely between products.
Both oral and topical routes may offer some benefit, but topical application may be better tolerated for individuals concerned about systemic effects. Choosing between the two depends on personal goals, medical history, and guidance from a dermatologist.
Possible Side Effects of Saw Palmetto
Saw palmetto is generally considered safe, but side effects can occur, particularly when taken orally. The most commonly reported issues include mild digestive upset, nausea, diarrhea, or abdominal discomfort. Some people experience headaches, dizziness, or fatigue.
Less commonly, saw palmetto may cause liver enzyme changes, so those with liver conditions should use caution.
Because it can affect hormone metabolism, it may interfere with certain medications, including blood thinners and hormone therapies. Topical saw palmetto tends to cause fewer systemic issues, though some users may notice scalp irritation or allergic reactions.
While typically well tolerated, long-term safety data is limited, making medical guidance important before starting supplementation, especially in those with other health concerns.
Who Should Not Use Saw Palmetto
Saw palmetto is not suitable for everyone. Women who are pregnant, trying to conceive, or breastfeeding should avoid it, as its hormonal effects may be unsafe during these stages.
Individuals taking anticoagulants or antiplatelet medications should also avoid saw palmetto due to the risk of increased bleeding.
People with hormone-sensitive conditions, such as breast or prostate cancer, should exercise caution, as the supplement may interfere with hormone metabolism. Additionally, those with liver disease should avoid saw palmetto unless cleared by a physician.
Since supplements are not regulated as strictly as prescription drugs are, product quality and potency can vary, making professional guidance essential. A dermatologist or physician can help determine whether saw palmetto is safe and appropriate for addressing hair loss.
Comparing Saw Palmetto vs. Finasteride DHT Reduction Potency
Finasteride and saw palmetto both reduce dihydrotestosterone (DHT), but their potency differs significantly.
Finasteride has been shown to lower serum DHT by about 60–70%, leading to meaningful stabilization of hair loss and, in many cases, regrowth within 3 to 6 months. Continued use maintains hair density and slows further thinning for years.
Saw palmetto, by contrast, reduces DHT more modestly, with estimates ranging from 30–40%. Improvements in hair thickness and shedding may occur, but results tend to be less predictable and usually take longer to become noticeable.
While saw palmetto may help slow loss, finasteride is consistently more effective for both halting progression and achieving measurable regrowth.
Efficacy in Clinical Studies
When evaluating treatments for androgenetic alopecia, clinical evidence provides the clearest picture of how well different options work.
Finasteride has been extensively studied in large, long-term trials, offering reliable data on its ability to slow hair loss and encourage regrowth.
Saw palmetto, while increasingly researched, has been examined in smaller, shorter studies with varying methodologies, making its results less consistent and harder to generalize.
Long-term Finasteride Studies
In one particularly impressive study conducted on 532 Japanese men with androgenetic alopecia, participants were given 1 mg doses of oral finasteride daily for a period of 10 years.
At the end of the 10th year, 91.5% showed significant hair growth improvement, and the prevention of disease progression was evident in 99.1% of the men. No serious adverse reactions were noted.
Saw Palmetto Studies
A 2020 review of studies performed to evaluate the effectiveness of saw palmetto for hair loss found that 60% of participants treated with oral or topical forms showed an improvement in overall hair quality, 83.3% showed an increase in hair density, 27% showed an improvement in total hair count, and 52% showed stabilized disease progression.
An interesting 2-year study comparing the effectiveness of saw palmetto to finasteride found that 38% of patients treated with saw palmetto had an increase in hair growth compared to the 68% who experienced improvement with finasteride.
This reinforces the belief that although saw palmetto can lead to improved hair growth, finasteride is more effective in most cases.
Can You Combine Saw Palmetto With Finasteride?
Saw palmetto and finasteride both work by inhibiting 5-alpha reductase, the enzyme responsible for converting testosterone into dihydrotestosterone (DHT). Because they act on the same pathway, combining them may not significantly enhance results compared to finasteride alone.
However, some patients choose to add saw palmetto as a complementary approach, especially in topical formulations. While no major safety concerns have been identified with using both together, research on the combination is limited.
A dermatologist can help determine whether pairing them is worthwhile or if finasteride alone is the more effective option.
Consider Using a Finasteride Alternative
For individuals who cannot take finasteride or prefer a different approach, several alternatives exist. The most widely used is minoxidil, available in both topical and oral forms.
Unlike finasteride, minoxidil does not target DHT; instead, it prolongs the growth phase of hair follicles and increases blood flow to the scalp, encouraging thicker strands. It can benefit both men and women and is often effective for diffuse thinning as well as patterned hair loss.
Other options include platelet-rich plasma (PRP) therapy, which uses growth factors from a patient’s blood to stimulate follicles, and low-level laser therapy (LLLT), which may improve scalp circulation and cellular activity.
Some people may also consider dutasteride prescription, a stronger prescription DHT blocker (up to 90% reduction in DHT serum levels) or products with spironolactone, a medication often used in women that reduces androgen activity.
A dermatologist can help select the most appropriate option based on individual needs and medical history.
The Benefits of Combining Minoxidil and Finasteride
Using minoxidil and finasteride together targets hair loss through two complementary mechanisms: minoxidil stimulates follicles by prolonging the growth phase, while finasteride reduces DHT to prevent follicle shrinkage.
Combination therapy, especially when custom formulated, often provides superior results compared to either treatment alone, leading to greater hair density, thicker strands, and reduced shedding.
This approach can also help sustain long-term improvements, making it one of the most effective treatment strategies for androgenetic alopecia.
A Dermatologist Can Provide Guidance
A board-certified dermatologist can evaluate the type and severity of hair loss, assess hormonal factors, and review medical history to determine the safest and most effective treatment.
They can tailor therapy, monitor results, adjust dosages, and combine treatments, ensuring optimal outcomes while minimizing risks.
Saw Palmetto vs. Finasteride: The Bottom Line
Finasteride remains the most potent and well-studied option for reducing DHT and promoting hair regrowth, while saw palmetto offers a milder, natural alternative with fewer systemic risks.
For those seeking the strongest clinical results, finasteride or combination therapy with minoxidil is often recommended. Saw palmetto may be useful for patients preferring a gentler approach or supplementing other treatments.
Ultimately, choosing the right strategy depends on individual needs, making the decision between saw palmetto vs. finasteride a personalized one.
Talk to a board-certified dermatologist to discuss your goals and find the solution that is best for you.
Frequently Asked Questions
Does saw palmetto actually reduce DHT?
Yes, saw palmetto is believed to reduce dihydrotestosterone (DHT) by inhibiting the enzyme 5-alpha reductase, though its effect is milder than prescription options such as finasteride and dutasteride. Many people find modest improvements in hair density, but results vary significantly.
What is the strongest natural DHT blocker?
Among natural options, saw palmetto is the most studied for blocking DHT, but its potency is much weaker than finasteride or dutasteride. Other supplements, including pumpkin seed oil, green tea extract, and pygeum, have been investigated, yet clinical evidence remains limited compared to medications.
Is it safe to take saw palmetto and finasteride together?
Taking saw palmetto with finasteride is generally considered safe, but combining both may not significantly increase DHT reduction since they work through similar mechanisms. Because interactions and individual responses vary, it’s best to consult a dermatologist before using them together.
What is more powerful than finasteride?
Dutasteride is considered more powerful than finasteride because it blocks both type I and type II forms of the 5-alpha reductase enzyme, resulting in greater DHT suppression. However, it may also carry a higher risk of side effects, which is why it is less commonly prescribed for hair loss.
