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Oral Finasteride

Key Takeaways

Finasteride is the most powerful and popular treatment for male AGA patients worldwide.

It lowers the mean serum DHT levels by 71%, prostate DHT by 85% and scalp DHT by 64%.

Finasteride is very effective at halting the progress of hair loss and can also help regrow hairs since it is efficacious for up to 90% of users with many experiencing considerable regrowth.

Men taking finasteride should refrain from donating blood, trying to have children, and must keep it away from children and pregnant women.

The side effects of finasteride are uncommon and reversible after discontinuation. However, there are rare cases of persistent side effects which are being further researched.

Patients with a history of depression should take caution in taking finasteride as it may exacerbate depressive symptoms.

Finasteride reduces the risk for developing low grade prostate cancer and although it shows a higher risk for high grade prostate cancer (probably due to enhanced detection) it does not affect survival rate.

Finasteride ( Propecia) is a hair loss medication that works as a 5-alpha-reductance enzyme inhibitor.

What is Finasteride

Finasteride (also known as Propecia) is a hair loss medication that works as a 5-alpha-reductance enzyme inhibitor. Finasteride was first patented in 1984 and was approved for medical use in 1992. Originally, finasteride was intended for patients suffering from an enlarged prostate (BPH). It lowers serum Dihydrotestosterone (DHT) levels, leading to the prostate gland shrinking in size and improving BPH symptoms. Later on it was discovered that finasteride also halts the progression of hair loss and leads to some regrowth in patients suffering from AGA as well. This lead to finasteride being widely used as a hair loss medication for men suffering from AGA. Today, finasteride is the most powerful and popular treatment for AGA patients worldwide.

Finasteride ( Propecia) is a hair loss medication that works as a 5-alpha-reductance enzyme inhibitor.

Mode of Action

Circulating Testosterone is converted into DHT utilizing the 5-alpha-reductance enzymes and proteins. DHT has a 2 – 5 times higher affinity to attach to the androgen receptors in the body and is 10 times more potent than testosterone, making these two hormones different but complementary.

5-alpha-reductance enzymes types I, II and III are expressed differently throughout the body in adulthood in various tissues. Investigating the medical database will reveal that these enzymes are expressed broadly within the body. 5-alpha-reductance enzyme type I is expressed in the lung, brain, intestine, skin, prostate, testis, and stomach while type II is expressed in the prostate, lung, liver, kidney, brain, testis, and skin. Finally, type III is expressed in kidney, testis, intestine, brain, liver, uterus, pancreas, skin, and prostate.

In balding scalps, the activity of the 5-alpha-reductance enzymes is increased making the inhibition of the responsible enzyme a suitable treatment option for AGA. While 5-alpha-reductance enzyme type I is mainly expressed in the skin and the sebaceous glands that produces sebum, type II is expressed more within the hair follicle making it the primary target for treating hair loss.

Finasteride potently inhibits the 5-alpha-reductance enzyme type II and to a lesser extent type I (although at a much higher dose than is being prescribed). It has also been shown to inhibit 5-alpha-reductance enzyme type III at a similar potency in a experimental setting using human cells in vitro. This leads to finasteride lowering the mean serum DHT levels by 71% after 24 weeks of use while reducing the DHT levels within the prostate by 85%. Finasteride also reduces scalp DHT levels by 64% making it effective at increasing hair count after a six month use.

 

Treatment Protocol

Finasteride is prescribed at a 1 mg/day dose for the treatment of AGA. Finasteride at this dosage has an average a bioavailability of 65% which leads to an average peak plasma concentration of 9.2 ng/ml 1 – 2 hours after intake. The half-life of finasteride (time it takes for the body to excrete 50% of the absorbed dose) for men in the age range of 18 – 60 years is approximately 5 – 6 hours. This time increases to 8 hours for men over the age of 70 as body’s ability to process and detoxify is diminished with age. Finasteride is extensively metabolized by the liver and is excreted through urine and feces. This relatively short half-life means finasteride should be taken consistently.

The bioavailability of finasteride is not related to food intake and therefore can be taken with or without meals anytime during the day.  

In order to halt the progress of hair loss and maintain the results achieved by taking finasteride, it should be taken consistently for life. This is due to the fact that patients who quit finasteride experience an excessive shed within a couple of months. In these patients, the hair loss will return to its pre-finasteride stage and will continue to get worse as AGA progresses. 

Finasteride ( Propecia) is a hair loss medication that works as a 5-alpha-reductance enzyme inhibitor.

Expected Results

Finasteride is very effective at halting the progress of hair loss and maintaining the current hair count. It can also help regrow hair as this large Japanese study of 3177 men taking finasteride found that it was efficacious for up to 90% of users with many experiencing considerable regrowth. It should be noted that patients should not expect immediate results since the benefits of finasteride will become apparent over time (at least up to three month). This long term study found that patients experienced an overall increase of 10% in hair count in a two year period. 

Precautions

 

Men taking finasteride should refrain from donating blood for up to one month after quitting due to the drug`s half-life.

Finasteride should not be taken by pregnant women and children as it can have serious effect on the sexual development of the fetus and children.

Finasteride might interact with other medications (such as some antifungals, HIV medications, Nefazodone and etc.). If you are taking other medications, carefully read the medication`s instructions and consult your doctor to either adjust the dosage or change the medication.

Finasteride should not be taken by men who are trying to reproduce. Finasteride is shown to alter the sperm parameters in men which tends to be temporary and is expected to return to normal after discontinuation.

Men taking finasteride should inform their doctor especially when undergoing a PSA test as finasteride affects PSA levels.

Side Effects

Like many medications, finasteride has possible side effects that should be considered. It is important that hair loss patients discuss the long term impact of finasteride with their doctors before taking it as finasteride is meant to be taken over a life time for AGA treatment. Finasteride has gained a controversial reputation due to its side effects and therefore an evidence based look into the long term effect of finasteride is crucial in understating the risks. It is vital that patients have a full understating of the possible risks of this medication before they choose to take it for life since often even AGA doctors are not aware of these risks and do not discuss them with their patients. Finasteride has become so popular that most AGA doctors prescribe them without hesitation and do not take time to explain these risks with their patients.

In short, the side effects of finasteride are uncommon and reversible after discontinuation. However there are some rare cases of persistent side effects which are being researched and should be considered. 

Sexual Dysfunction  

Considering most studies done on the sexual side effects of finasteride, these side effects often occur at a rate of 2.1 – 3.8%, with erectile dysfunction (ED) being the most common followed by loss of libido. These side effects were observed early in the therapy and resolved after discontinuing treatment. In some cases the side effects went away over time on continuous use of the drug. 

In order to understand the true prevalence of side effects, we should consider the placebo effect. Since finasteride has gained a bad reputation, many men who are concerned about these side effects might experience them due to their anticipation. This is the placebo effect (or in this case nocebo effect since the effects are negative.) where the anticipation of sexual side effects will lead to physiological anxiety which then turns to a physical sexual dysfunction. 

This nocebo effect is apparent in this study were men who were informed about the possibility of the sexual side effects reported a higher rate of ED than the control group. Furthermore, the side effects were reversible within 5 days after discontinuation.

This 5 year study showed that the sexual side effects of finasteride occurred in less than 2% of men and were reversible in all men who stopped the medication. Not only that, but also the rate of side effects decreased to less than 0.3% by the fifth year in men who continued the treatment.

A large prospective study called Prostate Cancer Prevention Trial (PCPT) which aimed to investigate the possible use of finasteride in preventing prostate cancer, employed 17,313 men taking finasteride at a higher dose of 5mg/day for 7 years. After analyzing the rate of sexual dysfunction, the authors concluded that the rate of sexual side effects are minimal and should not impact the decision to take this drug.

Moreover, there rare case reports of patients developing Gynecomastia while being on finasteride. This is mainly due to the effect finasteride has on Estrogen levels. Finasteride increases both Testosterone and Estrogen by about 15% each. In some rare cases, this might lead to changes in breast tissue in men. If you experience changes in your breast tissue while on finasteride consult your doctor immediately.

Depression 

Another less known possible side effect of finasteride is an increased risk of depression. This can be seen in this study which looked at the long term safety of finasteride in the PCPT group. The study concluded that people taking finasteride might have up to a 10% increases risk in developing depression. Another prospective study of 144 men suffering from AGA found that finasteride might induce depressive symptoms. It is quite unclear how finasteride might induce depression.

finasteride might induce depressive symptoms in patients with a history of depression.

It is believed that finasteride impacts several steroid hormones within the brain due to the fact that the brain also relies on the 5-alpha-redutance enzyme for the conversion of several steroid hormones, leading to changes in mood and possibly depression.

Therefore, patients with a history of depression should take caution in taking finasteride as it may cause further depressive symptoms in these at risk population.      

Post Finasteride Syndrome (PFS) 

 

Although finasteride has been successfully used to treat male pattern hair loss and benign prostatic hyperplasia for decades now, only recently rare case reports of patients suffering from persistent sexual dysfunction and depression which persists long after its discontinuation has come to light.

This phenomena is called Post Finasteride Syndrome (PFS) where in rare cases patients who begin taking finasteride and in some cases in patients who quit taking finasteride, an onset of symptoms occurs. These symptoms include: loss of libido, erectile dysfunction, reduced penile sensation, gynecomastia, cognitive impairment, depression and etc. These symptoms persists for months and years depending on each case.

This study was one of the first published works mentioning this rare side effect were researchers recruited 71 men who self-reported suffering from PFS online. A follow up study of 54 participants of the initial paper aimed at evaluating the persistence of these symptoms found out that up to 89% of the PFS cases still reported persistent side effects after 16 months from the original report.

Another research group analyzed the neuroactive steroid levels in the cerebrospinal fluids of PFS patients and concluded that these neuroactive steroids are impaired in PFS patients, leading to depressive symptoms despite the discontinuation of finasteride. A follow up study further approves these findings.

Although what causes PFS is still unclear, researchers believe there might be a genetic factor involved. It is unclear if these symptoms are induced by finasteride or they are inherent to the patient. Post Finasteride Syndrome is a serious but rare condition and patients who experience these side effects should consult their doctor immediately and seek support.  

 

Long Term Safety

 

Since Finasteride is intended for life time use, establishing its long term safety is essential. This study on the long term safety of finasteride looked at conditions such as Ischemic and thrombotic events, Diabetes, Osteoporosis, Dementia, Depression and etc. and only found a modest increase in risk for depression.

Another point of concern for finasteride is its impact on prostate cancer risk. The PCPT study’s goal was to investigate if finasteride can protect against prostate cancer. The study found that finasteride can lower the risk of low grade prostate cancer while it showed an increase risk in developing high grade prostate cancer. The increase in the risk of high grade prostate cancer was analyzed further in this study and it was concluded that the increased risk is probably due to enhanced detection. Due to the effect finasteride has on serum PSA level and prostate size, detecting prostate cancer on patients taking finasteride becomes more likely since finasteride helps increase the accuracy of these detection methods. In other words, since finasteride makes the prostate shrink, it’s easier to find cancer if the patient has it while for people not taking finasteride, it’s easier to miss cancer diagnosis. This means that finasteride made it easier for doctors to find the high grade prostate cancer and it may not have caused it.

This study looked at the long term survival rate of the participants in the PCPT study and found that despite the higher rate of high grade prostate cancer in the finasteride group, the survival rate between the group taking finasteride and the placebo group was the same.

 

The impact of finasteride on the risk of prostate cancer is still debated and more data is needed. With that, the current data shows that finasteride reduces the risk for low grade prostate cancer and although there is a higher risk for high grade prostate cancer (probably due to enhanced detection) it does not affect survival rate. It is crucial for patients taking finasteride to inform their doctor while being screened for prostate cancer since finasteride lowers the PSA levels. This way a more accurate screening can be achieved by adjusting the PSA levels accordingly based on how long the patient has been taking finasteride. 

Review Our Case Studies

To see the results of finasteride  along with other treatment options, review our case studies and read about other patients success stories. 

You are a good candidate for Oral Finasteride treatment if:

 

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Are suffering from AGA

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Willing to take finasteride daily over a life time

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Do not have a history of depression

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Are not trying to have children

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