|Skin whitening ingredient||Description||How it works||Efficacy||Safe to use
on darker skin?
|Arbutin||A hydroquinone derivative (glycosylated benzoquinone) extracted from the bearberry shrub.||Inhibits tyrosinase to prevent the formation of melanin.||Arbutin found to inhibit melanin production in B16 cells induced with alpha-MSH and decreases tyrosinase activity. Less effective than kojic acid.||Yes.|
|Alpha-Arbutin||Alpha-Arbutin is an epimer of arbutin (4-hydroxyphenyl alpha-glucopyranoside)||Inhibits tyrosinase to prevent the formation of melanin. Said to have a stronger effect than Arbutin.||Melanin synthesis was reduced to 40% with 250 microg of alpha-arbutin.||Yes.|
|Magnesium ascorbyl phosphate||A stable vitamin C derivative||Suppresses melanin formation and protects against skin damage caused by UVB rays||A significant lightening effect was seen clinically
in 19 of 34 patients with melasma and solar lentigos.
|Kojic acid||Derived from fungus||Suppresses tyrosinase activity||Less efficacious than 2% hydroquinone. May cause contact dermatitis and erythema.||Yes.|
|Retinoic acid/Vitamin A acid||Boosts epidermal turnover, which promotes keratinocyte proliferation. Discharges epidermal melanin but not dermal melanin.||Tretinoin was used as monotherapy in a study on 38 African- American patients with melasma and 68%-73% of patients improved.||Yes.|
|Liquorice extract/Licorice extract||Glabridin||Inhibits tyrosinase activity (similar to kojic acid)||A combination product of 0.4% licorice extract, 0.05% betamethasone, and 0.05% retinoic acid was found to be effective in the treatment of melasma.||Yes.|
|Hydroquinone||An industrial chemical||Inhibits DNA synthesis and mitochondrial enzymes, has direct cytotoxic effects toward melanocytes. Also competes for tyrosine oxidation in active melanocytes.||One of the most effective inhibitors of melanogenesis in vitro and in vivo. Evidence of improvement is usually observed at 4-6 weeks. Tretinoin has been used to enhance the efficacy of hydroquinone.||Mostly safe, but risks exist. Exogenous ochronosis has been observed in black patients who have used high concentrations of hydroquinone for many years.
Thus, hydroquinone should be discontinued if no improvement occurs within 4-6 months.
|Mulberry extract||Derived from root of paper mulberry plant (Morus alba root).||Inhibits tyrosinase activity||Low concentrations shown to inhibit tyrosinase activity. Significantly lower compared to the concentrations needed for kojic acid and hydroquinone.||Yes.|
|Azelaic acid||Derived from yeast||Inhibits DNA synthesis and mitochondrial enzymes, has direct cytotoxic effects toward melanocytes.||A 20% concentration of azelaic acid is equivalent to 2% hydroquinone. However, azelaic acid has no lightening effect on normally pigmented skin, freckles, senile lentigines, and nevi. It has selective effects on only abnormal melanocytes.||Yes.|
|Niacinamide||Vitamin B3, niacin, nicotinamide||Inhibits melanosome transfer from melanocytes to keratinocytes.||In skin culture tests, niacinamide significantly inhibited the transfer
of melanosomes from melanocytes to keratinocytes (by 25–45%;
|Salicylic acid||A beta hydroxy acid (BHA) used to make aspirin||Increases cell turnover||Effective on minor skin discolorations.||Yes, in lower concentrations.|
|Undecylenoyl phenylalanine||Amino acid derivative. Commercial names include Skinwhite MSH and Sepiwhite MSH||Acts as an antagonist to melanocyte stimulating hormone (MSH). Prevents the start of melanin synthesis.||In testing, melanin levels were significantly reduced by 53% after 13 days.||Yes.|
|Topical corticosteroids||Several forms of corticosteroids include Hydrocortisone,
Clobetasol Propionate, Fluocinolone Acetonide or Betamethasone Dipropionate
|Unknown. It is possible that steroids reduce the production of melanocyte stimulating hormones (MSH).||Fast temporary skin lightening, however prolonged use is dangerous.||No.|
|Monobenzone||Monobenzyl ether of hydroquinone||Permanently depigments normal skin||Used for vitiligo patients.||Used for vitiligo patients only.|
|Mequinol||Monomethyl ether of hydroquinone||Cytotoxic to melanocytes (like hydroquinone)||Can be effective when used in conjunction with tretinoin||Yes, in lower concentrations.|