Anyone else get a whitish residue buildup on their temples from minoxidil/fin spray?

I’ve been using a compounded minoxidil + finasteride spray (with biotin and ketoconazole) for a couple years now. Lately I’ve noticed a buildup on my temples where I apply it. It’s a whitish residue — kind of like dandruff but thinner, and it only shows up on the exact area where I spray. It dries into a thin layer that I can peel off with my nail, almost like a film sitting on the skin.

My concern is two things:

  1. I think this layer might be blocking absorption and reducing how well the treatment actually works.
  2. It’s mostly on the temple/hairline area where I apply, and that’s also where I feel like my hairline has been worse lately.

For context, I’m on the spray/solution form (propylene glycol vehicle), so switching to foam isn’t an option since I need the compound.

A few questions for anyone who’s dealt with this:

  • Did you get the same kind of whitish buildup, and did it affect your results?
  • What actually cleared it? (I’ve started using a salicylic acid shampoo a couple times a week and micellar water in the mornings.)
  • Did changing your application routine or timing help?
  • Anyone move to oral min/fin because of this and notice a difference?

Appreciate any advice — trying to figure out if this is common or if I should be doing something differently. Thanks.

The white residue is common with topical treatments, mainly due to propylene glycol. It might help to ensure your scalp is clean before applying, consider adjusting application timing, or using a moisturizer afterward. Oral treatments can eliminate topical residue but watch for side effects. Salicylic acid and micellar water should help remove buildup.