Vitamin C (ascorbic acid) is a natural antioxidant that can inhibit tyrosinase to prevent melanin formation and reduce inflammation to minimize post-inflammatory hyperpigmentation.
Meanwhile, natural vitamin C is unstable, and different compounds are used to stabilize it, but changes in its structure may make it less effective for the skin. Studies show that a concentration of at least 10% is needed to be effective, and combining it with other ingredients can enhance its efficacy. It’s not enough to consume vitamin C orally since only a small portion reaches the skin, and topical application is more direct and effective.
Similarly, vitamin E is a natural antioxidant that can indirectly inhibit tyrosinase to lighten hyperpigmentation. However, its effect may not be significant if used alone, so it’s often combined with vitamin C to enhance its effectiveness. Hence, some products are labeled as C+E.
Niacinamide, a derivative of vitamin B3, is a common ingredient in whitening products. It has been proven to effectively inhibit melanosome transfer to reduce the melanin count in keratinocytes, resulting in fairer skin. Unfortunately, the effect slows down after four weeks, making it a mild whitening agent with few side effects.
Oligopeptides, like Lumixyl™, have been found to improve stubborn epidermal melasma with minor side effects. However, there is a scarcity of clinical data, so further research is needed.
Licorice extract is a pure natural essence that can inhibit tyrosinase and has anti-inflammatory and anti-allergic properties. It’s mild and rarely causes irritation or sensitivity, so many skincare products include this ingredient.
Soy protein is also a pure natural tyrosinase inhibitor that rarely causes irritation or sensitivity, but its effect is mild and takes a long time. Drinking soy milk is rumored to whiten the skin, which might be due to this ingredient, but don’t expect too much from it.