Is Propecia Making My Hair Lighter in Color?

Dear Dr. Rassman,

First of all, your website is very helpful and I commend you for offering your expertise.

My question is about a return to natural hair color while on Propecia. I am 28 years old with thinning hair, which has always been naturally thin but I am definitely balding recently. My hair is blonde but has darkened a bit over the years (a dirty blonde now). I have been on .5 mg propecia every day/every other day for 2 months now.

I noticed that much of the hair I lose is shorter, thinner, and a black color compared to the rest of my healthier hair strands. But recently since I started on propecia, the base of the hair falling out is a very light color, while dark towards the end. The lighter part at the root is about 2 cm or so and matches my more ‘natural’ hair color.

Is this an effect of Propecia? Does it mean that Propecia is having a positive effect returning my hair color/strength/thickness to it’s natural state? Why would thinner hairs be so dark in the first place?

Thanks for any answer you can give!

Miniaturized hair is lighter in color due to less melanin pigments present in each hair. Propecia can help thicken the miniaturized hair and by doing that make new hairs look darker. The light hair that you are losing may be the cycling miniaturized hair. Since you recently started taking Propecia, you may gain some of the original color back in the growing hair. Your miniaturized hair may continue to grow for a year or more and may eventually stop growing if Propecia can not keep it at bay. That is the reason most patients will see some return in color during the first year of taking the medication.