Finasteride, often known by brand names like Propecia or Proscar, is a medication primarily used to address male pattern hair loss, also called androgenetic alopecia. It works by targeting the enzyme 5-alpha reductase, which is responsible for converting testosterone into dihydrotestosterone (DHT). By inhibiting this enzyme, finasteride significantly lowers DHT levels in the body, including in the scalp, thereby reducing DHT’s detrimental effects on hair follicles.
Reversal of Hair Growth Benefits
Lowering DHT helps to halt or even reverse the miniaturization process of hair follicles, allowing them to grow thicker, healthier hairs. This suppressive effect on DHT levels is sustained only as long as the medication is actively present in the body.
Once finasteride treatment is discontinued, the body’s DHT levels will return to pre-treatment levels. This increase in DHT means that the hair loss process, previously slowed or stopped by the medication, will resume. Any hair gained or preserved during finasteride use will likely thin and fall out, eventually reverting to its pre-treatment state.
The hair follicles, no longer protected from the effects of DHT, will again undergo miniaturization, leading to a reduction in hair density and thickness. This reversal of benefits is a predictable outcome of stopping finasteride, as the medication’s positive effects on hair depend on continuous use.
Changes in Side Effects
Common side effects associated with finasteride, such as decreased libido, erectile dysfunction, or reduced ejaculate volume, are linked to the drug’s effect on hormone levels. For most individuals, these side effects resolve or diminish once finasteride is discontinued, as the body’s hormone levels, specifically DHT, begin to normalize. Clinical trials indicate that between 96% and 98% of men see these side effects disappear after stopping the medication.
The resolution of these effects occurs within weeks to a few months after cessation. However, the exact timeline and severity of resolution can vary among individuals. In some rare instances, a constellation of persistent symptoms, often referred to as Post-Finasteride Syndrome (PFS), has been reported.
PFS involves a range of sexual, physical, and neuropsychiatric symptoms that may continue for months or even years after finasteride discontinuation. While the exact mechanisms and prevalence of PFS are subjects of ongoing research, it is acknowledged as a serious concern for a small subset of users.
Expected Timeline of Effects
The effects of stopping finasteride are not immediate, as the drug needs to clear from the body and DHT levels must rise again. Finasteride has a relatively short half-life, around 5 to 6 hours, meaning half the drug is eliminated from the system. Most of the medication is cleared within 24 hours of the last dose.
However, the biological effects on DHT levels take slightly longer to fully reverse; DHT levels return to pre-treatment baselines within about two weeks after stopping the medication. Consequently, the resumption of hair loss progression may become noticeable within a few months, around 3 to 6 months, as the hair growth cycle is affected by the increased DHT. It can take up to 12 months for hair loss to return to its full pre-treatment extent.
Similarly, any improvement or worsening of side effects becomes apparent within weeks to a few months as hormone levels recalibrate. Individual timelines can vary based on factors like genetics, age, and how long finasteride was used. For instance, long-term users might experience a more gradual return of hair loss compared to short-term users.
Important Considerations Before Stopping
Before making any decisions about discontinuing finasteride, consulting a healthcare professional is recommended. A doctor can discuss the reasons for stopping the medication, provide guidance on managing expectations regarding hair loss, and address potential changes in side effects. They can also explore alternative treatment options for hair loss if desired, such as topical minoxidil or other medications.
Abruptly stopping finasteride is not advised, especially if the medication was also prescribed for conditions like benign prostatic hyperplasia (BPH), as symptoms may return. Gradual tapering might be suggested in some cases to help the body adjust, though there is no universally established tapering protocol. Understanding personal hair maintenance goals and having realistic expectations about post-finasteride outcomes are also important aspects of this discussion.