Persistent Erectile Dysfunction in men using α-reductase inhibitors, finasteride, or dutasteride

What are α-reductase inhibitors?

5-alpha-reductase inhibitors are a group of medicines that block the action of 5-alpha-reductase, the enzyme that converts testosterone into dihydrotestosterone.

They are used in the treatment of an enlarged prostate gland (benign prostatic hyperplasia) and male pattern hair loss. Drugs in this class are finasteride (marketed as Proscar [finasteride 5 mg] and Propecia [finasteride 1 mg]) and dutasteride (marketed as Avodart).

Finasteride is prescribed to people suffering from hair loss which is faced by most of the men.

What is Persistent Erectile Dysfunction?

Persistent erectile dysfunction is the inability to attain/maintain erections that are necessary for satisfactory sex for more than 90 days.

Reasons for Erectile Dysfunction in men exposed to 5α-RI 

An estimated 40 million men have prescribed finasteride for androgenic alopecia in 2020. Prescribers and patients might reasonably expect that accurate information would be available about the frequency, severity, and persistence of a common adverse effect of a drug approved for marketing more than two decades ago and prescribed to an estimated 2.6 million men annually.

A comprehensive review of a total of 73 papers on medical therapies for BPH was conducted, with a focus on the effects of different pharmacological agents on sexual function. The review revealed that finasteride is infrequently associated with problems of ejaculation (2.1-7.7%), erection (4.9-15.8%), and libido (3.1-5.4%).

There were mainly two reasons for Erectile Dysfunction in men exposed to finasteride

  1. The role of the nocebo effect in the causation of ED due to finasteride has been investigated. Nocebo effect refers to an adverse effect that results from the psychological awareness of the possibility of the side effects but is not a direct result of the specific pharmacological action of the drug. In this study, the group informed about the sexual adverse effects of finasteride reported increased incidence of ED, when compared to the group without information.
  2. The duration of 5α-RI exposure was a more accurate predictor of Persistent ED than many known risk factors, including age, hypertension, diabetes mellitus, cigarette smoking, ethanol abuse, obesity, and depression. Duration of finasteride exposure proved to be a more accurate predictor of sexual dysfunction than higher dose vs lower dose of finasteride, likely reflecting that finasteride exerts near-maximal inhibition of 5α-DHT synthesis at a dose of 1 mg.

Among young men with 5α-RI exposure, the duration of 5α-RI exposure was a more accurate predictor of PED than all other assessed risk factors. For every 108 young men exposed for >205 days to the finasteride dose typically used for androgenic alopecia (≤1.25 mg/day), one additional young man experienced PED when compared to those men with shorter exposure. The median duration of PED in young men was 1,534 days.


The reasons for Erectile Dysfunction in men exposed to 5α-RI  are mostly psychogenic and pharmacological, these can be reversed by contacting a doctor.

Consulting a doctor can reveal the reason for your erectile dysfunction and “The ED Clinic” is offering a free consultation with the best doctors in the field. Men need to muster up the courage to seek professional help from a doctor or a qualified clinical sexologist. Just taking this step will get them on their way to recover not only their sex life but their relationship as well. They need not worry about their privacy as clinics like “The ED Clinic”  take full care to make sure all privacy details are just that- Private.

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