That said, suggestions have been made that high doses of oral Vitamin C in the range of 1,000 mg to 3,000 mg may be needed to lighten skin.
4 weeks is usually the golden rule for beginning to see changes - it's allowed your skin to go through at least one renewal cycle with this skin-changing ingredient. At this point, your skin should have a subtle change in radiance, which is something you'll notice will stick around as long as you keep using Vitamin C.
Vitamin C is essential for an even skin tone and a glowing complexion. The daily requirement of vitamin C is 90 mg in men and 75mg in women in normal, healthy conditions. Citrus fruits such as lemons, tangerine, grapefruit, etc.
It inhibits melanin synthesis through downregulation of tyrosinase enzyme activity. It is widely used in dermatology as a treatment modality in depigmentation of hyperpigmented spots on the skin. It has also been used for treatment of gingival melanin hyperpigmentation.
Does Vitamin C Affect Skin Color? No. Vitamin C helps fade hyperpigmentation caused by the overproduction of melanin, but it won't change the natural color of your skin. It will lighten darkened areas caused by overexposure to the sun, free radicals, heredity and hormones.
The tetrahexyldecyl ascorbate is the stable oil soluble form of vitamin C that also penetrates your skin to help brighten and provide radical protection.”
Vitamins can be used to lighten your skin and lighten dark spots. Three of the best vitamins for lightening dark spots are vitamin C, vitamin B12, and vitamin E. Vitamin C helps your skin produce more collagen while inhibiting the formation of melanin.
Vitamin C lightens skin by inhibiting the amount of melanin your pigment skin cells generate. When applied topically, vitamin C interacts with tyrosinase, the main enzyme responsible for the conversion of the amino acid tyrosine into melanin, thereby reducing pigmentation.
Skin benefits of vitamin C
A few clinical studies have demonstrated that vitamin C can improve wrinkles. One study showed that daily use of a vitamin C formulation for at least three months improved the appearance of fine and coarse wrinkles of the face and neck, as well as improved overall skin texture and appearance.
As you may already know, vitamin C in the form of ascorbic acid (specifically L-ascorbic acid) oxidises easily. This is when it decomposes and turns into a number of other substances that likely have much less benefits for skin, and it gradually darkens in colour during this process.
Does Vitamin C really darken my skin? No, it does not. It may stain your skin but it cannot darken your skin.
Might Lighten Dark Spots
Vitamin C-based skin care products may lighten patches that are darker than the rest of your skin, called hyperpigmentation. In one study, vitamin C applied to the skin for 16 weeks significantly cut down on these spots.
The upper limit for vitamin C in adults is 2,000 mg. Individuals with chronic liver disease, gout, or kidney disease are recommended to take no more than 1,000 mg of vitamin C per day. High vitamin C intakes have the potential to increase urinary oxalate and uric acid excretion.
Dr. Chiu warns that because vitamin C is a skin-care “active”—meaning it's particularly potent—applying too much of it on your face can potentially lead to more breakouts or irritation. Keep it to a max of two applications a day when a formula that has no more than 10% vitamin C each time.
Vitamin C can be very acidic, and serums can cause skin irritation in some people, particularly in high concentrations. When using a vitamin C serum for the first time, apply a thin layer every other day and gradually increase to daily applications.
A Glutathione efficacy in skin lightening works only if it is taken with Vitamin C at least equal or twice its dosage. Standard dosage is 20-40 mg/kg of body weight for 3-6 months once or twice in a day and best if taken at night 2-3 hours after last meal for better absorption.
Vitamin C is an effective skin lightener that has been described as a melanogenesis inhibitor due to its inhibition of tyrosinase and reduction of melanin and melanin intermediates, such as dopaquinone.
Vitamin C aids in the whitening process by priming the skin cells and making them more susceptible to the effects of Glutathione. Additionally, research suggests that Vitamin C itself may possess some whitening and brightening properties.
The way it works is that Vitamin E helps the skin absorb Vitamin C better, boosting its brightening effects. Ideally, after cleansing toning, apply Vitamin C first, and then Vitamin E.
The upper limit for all adults is 2,000 mg a day. Although too much dietary vitamin C is unlikely to be harmful, large doses of vitamin C supplements might cause: Diarrhea. Nausea.
Taking too much vitamin C can cause side effects, including: Nausea, vomiting and diarrhea. Heartburn. Stomach cramps or bloating.
The recommended daily dose of glutathione for adults ranges from 500-2,000 mg per day when taken orally, or 10-20 mg/kg body weight when administered intravenously (IV). To maximize its effects, it is best to split up doses rather than take a single large dose each day.