Key Takeaways
Skincare should be layered from thinnest to thickest
Jo explained that lighter, smaller-molecule products like serums should go on first so they can absorb into the skin's deeper layers, while thicker creams applied last help seal those active ingredients in.
Vitamin C works best as the first product in a morning routine
Jo recommended applying vitamin C immediately after cleansing and prepping the skin, since delaying it behind other products slows how quickly it can address concerns like discoloration.
Tretinoin should go on dry skin to minimize irritation
Jo noted that applying tretinoin to still-damp skin tends to increase irritation, so waiting for the skin to fully dry after cleansing or using a prep product can make the product more comfortable to use.
Stacking too many active ingredients at once can backfire
Jo cautioned against combining multiple exfoliating or active products, like an acid cleanser, a glycolic toner, and a retinol, in the same routine, since the combination can irritate the skin rather than improve it.
Skipping moisturizer can make oily skin worse, not better
Jo explained that skin stripped of moisture often compensates by producing more oil, so using a moisturizer — even for oily skin — can help regulate oil production rather than add to it.
