Finasteride: Dosage, Uses & side effects for hair Loss

What is Finasteride?
Finasteride is a 5-alpha reductase inhibitor, mostly used in the management of male pattern hair loss and stimulation of re-growth of hair in men. It is also indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate.
Finasteride is commonly sold under brand names as "Proscar" (for benign prostatic hyperplasia) and "Propecia" (for male pattern hair loss).
Why Finasteride should be used?
Hair loss occurs when testosterone gets converted into DHT and binds to an androgen receptor which led to hair fall.
Hair loss occurs when testosterone gets converted into DHT and binds to an androgen receptor which led to hair fall.
So, to reduce hair fall, a DHT blocker like finasteride is necessary which will stop this conversion and can prevent hair fall.
How DHT causes hair fall?
Hair growth mainly starts from the cells present at the base of hair shaft known as dermal papilla.
These cells divide and proliferate to form new hair follicles.
Dermal papilla cells carry all the essential nutrients required for the hair growth along with androgen (hormone).
When hair follicles exposed to DHT, hair growth retards and disrupted resulting in hair miniaturization and hair loss.



How Finasteride works and helps to reduce hair fall?
Finasteride is a specific inhibitor of type II 5 alpha reductase, an enzyme responsible for the conversion of testosterone to DHT.
It regulates the production of dihydrotestosterone.
Finasteride acts on the binding site of DHT and stops the transmission of DHT to further hair follicles.
DHT causes the shrinkage of hair follicles and shortens the growing phase.
By lowering the DHT levels, finasteride reverses the harmful effects on hair follicles and stimulates re-growth of hair.



Finasteride can decrease DHT concentrations in the serum and scalp up to 60-70% approximately.
How finasteride is different from natural DHT blockers?
Finasteride is approved by FDA for the treatment of hair loss.
Studies have shown that finasteride decreases serum DHT levels approximately by 71% while natural DHT blockers like saw palmetto decreases such by approximately 32%.
Finasteride can act both on the front area and on the vertex to reduce hair fall while saw palmetto prevalently in vertex.
Finasteride for female pattern hair loss
It is believed that women with hyperandrogenism might be more likely to benefit from finasteride treatment. Finasteride 1.25 mg or 2.5 mg daily, effectively promotes scalp hair growth.
Indications
Contraindications
Drug Interactions
Formulations
Finasteride is indicated for androgenetic alopecia in males. It stabilizes the male pattern hair loss in the males aged from 18-41 year old.
It is classified in the FDA pregnancy category. Women should not even touch this medicine in pregnancy
Hypersensitivity
Use in children or adolescents
Use in pregnancy
Lactation
There are no significant any drug interactions with clinically important which have been demonstrated with finasteride.
Active ingredient: Finasteride.
Inactive ingredients include:
Lactose monohydrate
Microcrystalline cellulose
Pregelatinized starch
Sodium starch glycolate
Hydroxypropyl methylcellulose
Hydroxypropyl cellulose
Titanium dioxide
Magnesium stearate, talc
Docusate sodium
Yellow ferric oxide and red ferric oxide
Mostly used Brands of Finasteride and price
Medical uses of Finasteride
Finasteride is used to treat
Male pattern hair loss
Overall risk of prostate cancer
Alone or in combination with other drug to treat benign prostatic hypertrophy
Acute urinary retention
Off label uses include
Hirsutism (excessive facial and/or body hair growth)
Hormone Replacement therapy
Topical Finasteride
Oral Finasteride has been known to associate with side effects such as erectile dysfunction, low libido due to decreased levels of DHT in blood.
A topical formulation of finasteride has been formulated along with minoxidil. Minoxidil helps finasteride in better absorption due to its vasodilator property.
A clinical trial has shown that 1mg of topical finasteride controls more DHT levels in scalp than oral finasteride. Meanwhile, both topical and oral administrations decrease almost similar DHT level in serum. But study also suggests that if you get a side effect from oral finasteride, most likely you will get a side effect from topical finasteride also.
Adverse effects of Finasteride
Post finasteride syndrome (PFS) usually occurs in patients taking finasteride. This symptom complex can be physical, sexual, as well as neurological. It is also known as 5 alpha reductase inhibitor syndrome. Few men may also complain of side effect such as 'brain fog' or cognitive impairment. This is the most discussed concept and still no clinical data is published.
Studies have shown that finasteride may be involved in altering the immune system of the body against carcinoma cells or cancer in aging men.
As finasteride inhibits the DHT, ratio of estrogen to androgen alters which can increase the risk of gynecomastia and male breast cancer.
Anatomy and Structure
How finasteride was discovered
Clinical data
Finasteride is a synthetically derived 4-azasteroid reductase. It is a specific inhibitor of steroid type II DHT, testosterone to 5 carboxamide. Its structural formula is;
Generic name of finasteride for the treatment of hair loss is Propecia which was originally developed and manufactured by Merck Pharmaceuticals.
P. Roy Vagelos (Merck's basic research chief) in 1975 was intrigued by the perception of decreased levels of DHT (Dihydrotestosterone) which led to the development of smaller prostates and increased hair growth. Dr. Vagelos then created a drug which could treat or mimic the condition.
Finasteride (1mg) was approved by FDA in 1997 under the brand name Propecia which was marketed by Merck.
Finasteride is a white crystalline powder and freely soluble in chloroform, alcoholic solvents but is insoluble in water.
Many scientific research or clinical studies have been conducted on Finasteride and various physical or chemical data have been collected which is as follows:
Frequently Asked Questions about Finasteride
Is Finasteride a steroid?
Can Proscar be used for Hair fall?
What is the difference between Finasteride, Proscar and Propecia?
What is 5AR and how it is related to finasteride?
Does Propecia work in older men?
Is topical finasteride as effective as Finasteride tablets?
How finasteride be used?
What is the recommended dosage of Finasteride?
What if a dose is missed?
What is the dose response of finasteride?
In a clinical study, 249 men with androgenetic alopecia underwent for scalp biopsies for the determination the effect of different doses of finasteride administered daily up to 42 days, on scalp skin and serum androgens.
What are the possible side effects of finasteride?
What precautions should be taken while using Finasteride or before using it?
About Author & Bibliography
Bibliography
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NOTE: This content of this post is written by the experienced dermotologist based on formal medical studies. It is reliable and scientifically verified and reviewed and edited by concerned doctors and health professionals to provide objective information on the diagnosis and treatment of diseases. If you are a doctor or health scientist and find inaccuracies, errors or omissions, please contact us at [email protected]
About Author: This post is written by Dr. Aman Dua, MBBS, MD, FISHRS having 14 year of experience in the fields of Dermatology and Hair Transplant. She is the Chief Dermatologist, Co-Founder & Managing Director At AK Clinics.
Reviewed by: This post is reviewed by Dr Kapil Dua, MBBS, MS, Dipl. American Board of Hair Restoration Surgery (ABHRS), Member, FUE Advancement Committee, ISHRS, USA to improve readability and authority of the written content.