Dutasteride

Dutasteride, like finasteride, belongs to the class of 5α-reductase inhibitors. It's primarily used to treat benign prostatic hyperplasia (BPH), an enlargement of the prostate. However, it has also been studied for its potential in treating male pattern baldness, or androgenic alopecia.

How Does Dutasteride Impact DHT Levels?

Dutasteride inhibits both type I and type II 5α-reductase enzymes, compared to finasteride which primarily inhibits only the type II enzyme. These enzymes are responsible for converting testosterone into its more potent form, dihydrotestosterone (DHT). By targeting both enzymes, dutasteride can reduce DHT levels more comprehensively. Studies have indicated that dutasteride can lower serum DHT levels by up to 90% or more.

Potent DHT Reduction

Due to its broader inhibition spectrum, dutasteride can decrease DHT levels more effectively than finasteride.

Potential Hair Regrowth

Some studies suggest that dutasteride may be more effective than finasteride in promoting hair regrowth and slowing hair loss in men with androgenic alopecia.

Effective BPH Treatment
Like finasteride, dutasteride is effective in treating benign prostatic hyperplasia. Once-Daily Pill
Similar to finasteride, it's taken orally once a day.

Downsides of Dutasteride

Sexual Side Effects
Dutasteride may cause decreased libido, erectile dysfunction, and other related side effects.

Longer Half-Life
The longer half-life means it stays in the system longer, which might prolong any potential side effects after discontinuation.

Unknown Long-Term Effects
Since it's a relatively newer medication compared to finasteride, the long-term effects are not as thoroughly studied.

Teratogenicity
Like with finasteride,dutasteride should not be handled by pregnant women due to the potential birth defect risks.

Mechanism of action compared

Finasteride

Target Enzyme
Finasteride primarily inhibits the type II 5α-reductase enzyme.

Efficacy
By targeting the type II enzyme, finasteride can reduce serum DHT levels by approximately 65-70%.

Usage Approved by the FDA for both male pattern baldness and BPH. Specificity: Its selective inhibition for the type II enzyme means that it has a narrower scope of DHT reduction compared to dutasteride.

Dutasteride

Target Enzyme Dutasteride inhibits both type I and type II 5α-reductase enzymes.

Efficacy This broader spectrum of inhibition allows dutasteride to reduce serum DHT levels by over 90%.

Usage
While approved for the treatment of BPH, it's used off-label for male pattern baldness due to its potential to further reduce DHT.

Specificity
Its broader inhibition means it impacts a wider range of DHT-producing processes in the body. Comparison and Implication:

The central difference in the mechanism of action between the two drugs lies in the scope of their enzyme inhibition. Since dutasteride inhibits both major types of 5α-reductase enzymes, it offers a more comprehensive reduction of DHT. This could imply a higher efficacy in treating conditions associated with DHT but might also carry an increased risk of side effects due to its broader action.

However, it's essential to note that the clinical implications of this difference can vary. For instance, while dutasteride might theoretically be more effective in treating hair loss due to its superior DHT reduction, it's not officially approved for this purpose in many countries. It has been approved in South Korean and Japan but is used off-label in many other countries like the UK. Both drugs have shown efficacy in their respective approved applications, and the choice between them should be based on individual clinical scenarios, potential side effects, and patient preference. Always consult a healthcare provider when considering these medications.

Reduced acne

Along with the side affects reported by users of finasteride, some of the more severe side effects are the impact on skin. As type 1 DHT is predominantly in skin, the androgen sensitive sebaceous glands will suffer from androgen starvation and stop producing the sebum that it once was. This reduction in sebum may reduce oily skin and hence lead to the clearing up of acne. Some users have reported back acne and face and neck acne clearing up for the first time in their lives. The power of altering androgen levels hence has a systemic effect on the body.

Topical Dutasteride

Dutasteride molecule, like the finasteride molecule, is not absorbed into the skin very easily due to its size. Bryan Johnson has been reported to add dutasteride injections into his PRP routine, which avoides the systemic affects of taking the pill orally and concentrates the effect in the areas it has been injected into the scalp.

Half life

Dutasteride has a significantly longer half life when compared to finasteride. Finasteride can be removed from the body within days, Dutasteride on the other hand will stay in the body for more than 6 months.

Limp Dick

A mouse model showered that administration of dutasteride for 4 weeks and 8 weeks had an impact on ability for erectile parameters. What this means is that dutasteride increase smooth muscle content and increased collagen in the penis. After discontinuation of dutasteride, there was no recovery for the 8 week group whereas the 4 week group recovered their erection ability.

Cycling on and off dutasteride As a man who is concerned about being able to get a hard on, this would signify that prolonged exposure to dutasteride will result in the ability to have a hard on ever again. This is a serious risk, and may indicate that dutasteride should only be taken intermittently with rest periods to allow for the penile cells to recover. The length of the rest period may need to be considered, with minoxidil as the only way to assuage androgen receptor activity during the off dutasteride period.

Effectiveness over Finasteride

Dutasteride has been found to eliminate more DHT than does finasteride. Some people have reported no hair recovery with finasteride but significant hair recovery from using dutasteride.

Impact on insulin

"Dual inhibition of 5αRs (which is what dutasteride is), but not inhibition of 5αR2 alone (which is what finasteride does), modulates insulin sensitivity in human peripheral tissues rather than the liver. This may have important implications for patients prescribed dutasteride."

Academic Research

• The efficacy and safety of dutasteride compared with finasteride in treating men with androgenetic alopecia: a systematic review and meta-analysis
• Prospective randomized study of sexual function in men taking dutasteride for the treatment of androgenetic alopecia
• Persistent erectile dysfunction in men exposed to the 5α-reductase inhibitors, finasteride, or dutasteride
• A 52‐week multicenter randomized controlled study of the efficacy and safety of add‐on dutasteride and imidafenacin to tamsulosin in patients with benign prostatic hyperplasia with remaining overactive bladder symptoms (DIrecT study)
• Persistent Erectile Dysfunction after Discontinuation of 5-Alpha Reductase Inhibitor Therapy in Rats Depending on the Duration of Treatment
• The Direct Inhibitory Effect of Dutasteride or Finasteride on Androgen Receptor Activity is Cell Line Specific
• T5α-Reductase Type 1 Modulates Insulin Sensitivity in Men