Hello! I purchased azelaic acid from FSS () in order to add it to a serum to lighten pigmentation on my face.
On the page it states the recommended dosage is 0,5-1,5%, however everywhere I see commercial products with concentrations from 10% (OTC), to 20% (prescription). It seems then that 1,5% will not have an effect. I have contacted the supplier, but they said they didn't have an answer as to how up to 20% could be included, and that their recommended usage rate was 'from their formulating results'.
I also asked abot specifics regarding solubulising, but they only repeated was was stated on the page, that it is 'Soluble in Glycerin &
Glycol', where I was hoping for more specifics on ratios. I've googled to find info on formulating, but found surprisingly little on the subject. Also all search results are saturated w. purchase-options for The Ordinary
(They have a azelaic acid suspension 10% available for less than a fiver, which makes me more confused than ever! but never mind, I'll be happy with advice on the part about the formulating.)
Hope for your advice on this. Many thanks in advance!