If you are looking for a relatively gentle glycolic exfoliator that is reinforced by repairing actives and won’t break the bank, then Mad Hippie Exfoliating Serum ($35) is well worth checking out. I have been testing it for about four weeks or so and found that, while not transformative, it helpfully manages reddish, roughish skin and does so without causing any flare-ups or irritation.
I started out using this Exfoliating Serum every other day and then in the third week of testing cut back to two to three times a week and always at night. This is because Mad Hippie’s serum exfoliates using glycolic acid and lactic acid, both AHAs. While I appreciate that they can improve the texture of the skin, I have become more cautious about using them since I came across recent research that gave me a better understanding of how they work. It seems that they create acidic conditions within the skin cell, ultimately resulting in its death and skin exfoliation (read more on how AHAs work).
On the brightening/lightening front, Mad Hippie has also included Gigawhite, which is a complex of six botanicals that are supposed to help fade age spots. There is no independent research on Gigawhite and I didn’t try this serum on age spots, but on skin that is a bit red and crepey from sun damage. There is also no independent research on Matrixyl 3000, although plenty of anecdotal evidence (as well my experience) suggests that this peptide complex helps promote collagen.
Exfoliating Serum also has apple stem cells, vitamin C, white tea, ceramide-3 and melatonin. All of these (and more) ensure that the good far outweighs the bad. However, there are a few things that I’d prefer Mad Hippie to seek out some alternatives for. Potassium hydroxide is an irritant that I am often allergic to even in rinse-off products. I had no bad reactions to this serum, but potassium hydroxide has been shown in animal studies to irritate at low levels. It is typically used as a pH adjuster (necessary for AHAs to work effectively). About half way down the ingredients list there is the possible neurotoxin, phenoxyethanol, and behentrimonium chloride, which is more usually seen in shampoos and can be irritating to the skin.