Issue link: https://www.ascpskindeepdigital.com/i/1489006
New member benefit! Get the ASCP SkinPro app at ascpskincare.com/skinpro 31 SKIN PHYSIOLOGY Regardless of the initial trigger of an inappropriate or excessive pigmentation response, like all biochemical processes in the body, skin darkening is mediated by hormones. (HQ), which is available in 2 percent (or lower) strengths without a prescription. Given the potential toxicity of this ingredient, which can permanently disable melanocytes and—with overuse—cause irreversible loss of pigmentation, you have to really want to eliminate your dark spots to use these kinds of concentrations. Even ordinary strengths of hydroquinone should be used carefully and only for short periods. Sometimes, dermatologists will prescribe hydroquinone combined with vitamin A molecules known as retinoids, particularly retinoic acid (RA). In addition to blocking the melanin-producing enzyme, RA increases pigment shedding. The effects of these retinoid molecules are more lasting than hydroquinone, and the two make for an effective, skin-lightening, one-two punch. Because of the potential irritation that is associated with these two powerful molecules, pharmacists will sometimes add anti-inflammatory steroids like hydrocortisone or triamcinolone to their HQ/RA compounds. A medication called mequinol, a by-product of hydroquinone, also has skin-lightening properties. It can be purchased over the counter and is marketed in the US in concentrations of 2 percent. In Europe and Asia, the molecule is considered a go-to antipigmentation agent and is used in strengths of up to 20 percent. Mequinol is often applied in conjunction with retinoids, which helps improve mequinol's penetration effects. While effective, mequinol overuse can cause melanocyte toxicity and permanent pigmentation loss. Another topical prescription ingredient that has been used to lighten the skin is resorcinol. With a molecular structure similar to hydroquinone, it makes sense that this substance would also provide therapeutic anti-melasma benefits. Unfortunately, this similarity makes resorcinol, like hydroquinone, potentially toxic, particularly in higher concentrations. A resorcinol solution blend that also contains hydroxy acids (lactic and salicylic), known as Jessner's solution or Jessner's peel, has been used as a skin-lightening and overall skin health mainstay since the 1940s. An amino acid derivative called tranexamic acid (TXA) also has beneficial effects on hyperpigmentation. Originally used to control postsurgical and excessive menstrual bleeding, TXA has been shown to reduce melanin synthesis. Interestingly, tranexamic acid benefits can be leveraged both topically and systemically. In addition to being available in creams and serums in strengths of 2–5 percent, TXA is safe and effective when taken twice a day for 12 weeks in doses of 250–500 mg. It's always best to recommend melasma clients seek a doctor's opinion if they haven't already. Their doctor can provide them with any necessary prescriptions before they see you for their next appointment.