Updated: Mar 31
Finasteride is one of, if not the, most effective and widely used hair loss treatments we have available. But, even though it has helped many people get their hair back, it is far from full proof.
Finasteride is effective in about 80-90% of people who take it and blocks about 70% of dihydrotestosterone (DHT) (1). Alternatively, a treatment that works similarly to finasteride: dutasteride, has been shown to be much more effective by blocking 90+% of DHT (2). You can read all you need to know about finasteride and dutasteride here.
Dutasteride is often used as a replacement for finasteride once it has been determined that finasteride is not effective for someone. Although dutasteride is harder to get (it is not FDA approved for hair loss) and will likely cost much more. This is why doctors generally have people try finasteride first (most doctors will not even consider a dutasteride prescription for off-label use unless finasteride is tried first).
But everyone is different, and no two people are going to react to a treatment in the same way. What takes one person 2 months to regrow their hair on finasteride might take another person ten years, and the next guy might not grow any hair at all. The only way to tell how you are going to react is to try it. But how are you supposed to know if you are the person who has to wait, say, 3 years to grow your hair back or if you are someone who has to swallow the pill of realization that finasteride is not going to work (pun intended)? And how are you supposed to know when the right time to switch to dutasteride is?
These questions are what we will be discussing throughout the article. There are many people who either use finasteride for way too long or discontinue it prematurely, all because they are uninformed about how it works and/or how to measure its efficacy.
Switching the dutasteride too early can cost time, money, and most importantly… hair. But, by detailing how finasteride works, as well as ways to measure efficacy, my goal is to hopefully save you from the hassle and stress of switching from finasteride to dutasteride at the wrong time so that you can save money and hair.
How do finasteride and dutasteride work?
Both treatments are called 5-alpha reductase (5-AR) inhibitors. This means that they work to actively block the enzyme 5-AR. This is important because 5-AR is what is responsible for turning testosterone into DHT (DHT is the androgen that is primarily responsible for male/female pattern hair loss).
By blocking 5-AR, both treatments can help suppress the number of DHT conversions happening throughout the body, therefore lowering the levels of DHT and reducing the hair loss that results from it.
There are two types of 5-AR, aptly named type 1 and type 2. What makes dutasteride more effective than finasteride is that it blocks both types of 5-AR, whereas finasteride only blocks type 2 (3).
For a lot of people finasteride is enough, but for some it isn’t, so let’s talk about…
When to switch from finasteride to dutasteride
Like stated earlier, most doctors make it mandatory to try finasteride before even considering giving a dutasteride prescription, which is why it is important to be able to tell when finasteride is or is not working for you.
The number one thing you have to practice is patience.
Finasteride’s main benefit is stopping the process of miniaturization. Essentially, miniaturization is the shortening of the anagen (growth) phase of the hair cycle, which, if left untreated, will shorten to a point where the hair doesn’t grow anymore (i.e. bald). If finasteride is effective, the anagen phase will begin to re-lengthen, although because of the nature of the hair cycle this process can take a long time.
Some people start to see results quickly; in about three months, but for most the baseline is generally around 6 months according to experts. It is recommended that you wait around a year to see the “final results”; at this point, whatever finasteride has done for you is going to be the most you can get out of it, and that can be different for everyone.
Finasteride is not always going to regrow hair because that is not it’s primary benefit. Instead, finasteride works to stop the progression of hair loss (other treatments like minoxidil and LLLT are more geared towards regrowth). Of course, there are always going to be people who get better-than-average results with any treatment, and in finasteride’s case it is those who regrow hair. But, if you are like most people you will not see any regrowth. That doesn’t mean that finasteride isn’t working though.
It could be that finasteride successfully stopped hair loss from worsening. For those who experience regrowth it is pretty easy to measure success on finasteride, but for those who don’t it can be much more difficult. If you are not one of the lucky few here is what I recommend:
While undergoing finasteride treatment, after three months:
-take weekly or bi-weekly pictures to measure visible hair loss
-vigilantly look for classic signs of hair loss such as hair on your pillow, in the shower, hair not styling like normal, and more (here is a more in depth article covering this)
-for men, monitor the density of your temples and crown, and for women the part line (these are the typical areas that lose the most hair due to pattern hair loss)
-if you are comfortable doing it, taper off other hair loss treatments that you use so that you can isolate any hair loss and/or results to finasteride alone
Doing those four things will help you remain aware and well in-tune with what is happening throughout the finasteride treatment process. But you must remember that you need to wait at least 3 months, but ideally closer to 6 months to 1 year before you make a definitive judgement about finasteride’s efficacy.
If there is anything you should take away from this article it is this:
Wait three months after starting finasteride to begin monitoring hair loss progression. If, at the 6-month mark (or year mark if you choose), you are both 1. Seeing signs of hair loss and noticing it worsen throughout progress photos, and/or 2. Not getting the results you expected from a hair loss treatment, then it is safe to say that it might be time to switch to dutasteride.
Dutasteride is more powerful than finasteride, and it is a great alternative if finasteride doesn’t work for you. But it also has potential side effects, which is why you should not only try finasteride first, but strategically measure your progress and give it a legitimate chance before switching.
Knowing how finasteride works is crucial to your overall success in overcoming hair loss. Waiting three months to start measuring and strategically monitoring your results for the next 3-6 months will allow you to be confident in your decision of whether or not to continue taking finasteride or if you need to switch to dutasteride.