Dutasteride vs Finasteride: Which Is Better for Hair Loss?

How DHT causes hair loss

To understand the finasteride vs dutasteride comparison, you need to understand DHT. Dihydrotestosterone (DHT) is a hormone derived from testosterone through an enzyme called 5-alpha reductase. In men who are genetically predisposed to male pattern baldness, DHT binds to receptors in the scalp and gradually shrinks hair follicles. Over years, this process produces thinner, shorter hairs until the follicle stops producing visible hair altogether.

Both finasteride and dutasteride work by inhibiting 5-alpha reductase, which reduces the amount of DHT your body produces. Less DHT means less damage to hair follicles, which can slow or stop hair loss and in some cases produce regrowth. The difference between the two drugs is how completely they block the enzyme.

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Finasteride: the established standard

Finasteride (brand name Propecia for hair loss) has been FDA-approved for treating male pattern baldness since 1997. It blocks type II 5-alpha reductase, which is responsible for about 70% of DHT production in the body. For most men, reducing DHT by 70% is enough to slow or stop hair loss, and many see noticeable regrowth within 6-12 months.

Finasteride is well-studied, widely available, and affordable. Through telehealth providers, generic finasteride starts at [around $24 per month at Keeps](/hair-loss/reviews/keeps-hair) and [$26 per month at Hims](/hair-loss/reviews/hims-hair). Using a service like [GoodRx Care](/hair-loss/reviews/goodrx-care-hair) and filling at a pharmacy with coupons, finasteride can cost as little as $3-8 per month.

The side effect profile is well-documented. Sexual side effects including decreased libido, erectile dysfunction, and reduced semen volume occur in roughly 1-2% of patients in clinical trials, though real-world reports vary. These side effects usually resolve when the medication is stopped. A small percentage of men report persistent side effects after discontinuing, a condition sometimes called post-finasteride syndrome.

• FDA-approved for male pattern baldness since 1997
• Blocks type II 5-alpha reductase (about 70% DHT reduction)
• Very affordable: $24-26/mo through telehealth, $3-8/mo with GoodRx
• Sexual side effects in roughly 1-2% of patients
• Well-studied with decades of data

Dutasteride: the stronger option

Dutasteride (brand name Avodart) blocks both type I and type II 5-alpha reductase enzymes, which reduces DHT production by about 90%. That is a significantly more complete suppression than finasteride achieves. The rationale for using dutasteride for hair loss is straightforward: if blocking 70% of DHT works well, blocking 90% should work even better.

The evidence largely supports this. Clinical studies have shown that dutasteride produces more hair regrowth than finasteride, particularly in patients with more advanced hair loss. A widely cited 2006 study found that dutasteride 0.5mg daily produced superior hair count increases compared to finasteride 5mg daily over 24 weeks. Longer-term data is more limited because dutasteride has not been studied as extensively for hair loss as finasteride.

The catch is side effects. Because dutasteride suppresses more DHT, it also causes more sexual side effects. The incidence of decreased libido, erectile dysfunction, and ejaculation disorders is higher with dutasteride than finasteride, though still relatively low in absolute terms. The same post-finasteride syndrome risk exists, and some clinicians theorize the risk may be slightly higher with dutasteride due to the more complete DHT suppression.

• FDA-approved for BPH, used off-label for hair loss
• Blocks type I and type II 5-alpha reductase (about 90% DHT reduction)
• Produces more hair regrowth than finasteride in studies
• Higher incidence of sexual side effects than finasteride
• Less long-term data for hair loss specifically

Cost comparison

Finasteride is significantly cheaper than dutasteride across the board. [Hims](/hair-loss/reviews/hims-hair) offers generic finasteride starting at $26 per month, while dutasteride pricing varies by plan. [Keeps](/hair-loss/reviews/keeps-hair) offers finasteride at $24 per month but does not carry dutasteride. [Henry Meds](/hair-loss/reviews/henry-meds-hair) offers both finasteride and dutasteride, with dutasteride at a higher price point.

For the most cost-conscious patients, getting a prescription through [GoodRx Care](/hair-loss/reviews/goodrx-care-hair) or [Sesame](/hair-loss/reviews/sesame-hair) and filling at a pharmacy with discount coupons is the cheapest route. Generic finasteride at a pharmacy can cost $3-8 per month. Generic dutasteride at a pharmacy typically runs $15-30 per month, depending on the pharmacy and dosage.

The cost difference adds up over time. Finasteride is a decades-old generic with deep price competition. Dutasteride, while also available as a generic, has less price competition in the hair loss context because fewer patients use it. For a year of treatment, the difference could be $100-300 or more.

Which one should you choose

For most men starting hair loss treatment, finasteride is the right first choice. It is FDA-approved for this purpose, well-studied, affordable, and effective for the majority of patients. Starting with finasteride also gives you a baseline to evaluate whether DHT inhibition works for your specific pattern of hair loss before considering a stronger option.

Dutasteride makes more sense for men who have been on finasteride for 12-18 months and are not satisfied with the results, or for men with advanced hair loss who want the most aggressive medical treatment available. The decision should be made with a clinician who can weigh the potential for additional regrowth against the higher side effect risk.

This guide is educational and not a substitute for personal medical advice. Eligibility, contraindications, and monitoring needs differ across individuals, which is why treatment decisions should be reviewed with a licensed clinician.

Both medications work best when combined with topical minoxidil, which stimulates hair growth through a different mechanism. Our [minoxidil vs finasteride guide](/guides/minoxidil-vs-finasteride) explains how the combination works. For provider comparisons, see our [Hims vs Keeps comparison](/compare/hims-vs-keeps) and our full [hair loss provider comparison](/hair-loss). To find the best place to get finasteride online, check out our [best finasteride online guide](/best-for/best-finasteride-online).