In theory, green tea extracts are great skincare ingredients because they contain powerful antioxidants (polyphenols). Tea plants can contain impressive quantity of the four polyphenol types: ECG, GCG, EGC, and EGCG (the most powerful in the pack). Unfortunately, these water-soluble antioxidants are very unstable. EGCG, for example, requires a low pH (below 4) to maintain stability, and a formulation with such pH can be irritating. It is degrades under influence of warm temperature, UV light and air. Looking at the formula of Zelens Tea Shot serum, I suspect that no particular effort went into stabilizing the green tea antioxidants, and this is why I doubt that this serum is effective beyond providing hydration benefits. I do not think it is worth the price tag. If you are after an antioxidant serum, I would recommend choosing a product with 10-20% of ascorbic acid and using it before its color turns to yellow/ orange (the change in color of the vitamin C products indicates that the ascorbic acid has oxidized and is no longer very effective.
In theory, green tea extracts are great skincare ingredients because they contain powerful antioxidants (polyphenols). Tea plants can contain impressive quantity of the four polyphenol types: ECG, GCG, EGC, and EGCG (the most powerful in the pack). Unfortunately, these water-soluble antioxidants are very unstable. EGCG, for example, requires a low pH (below 4) to maintain stability, and a formulation with such pH can be irritating. It is degrades under influence of warm temperature, UV light and air. Looking at the formula of Zelens Tea Shot serum, I suspect that no particular effort went into stabilizing the green tea antioxidants, and this is why I doubt that this serum is effective beyond providing hydration benefits. I do not think it is worth the price tag. If you are after an antioxidant serum, I would recommend choosing a product with 10-20% of ascorbic acid and using it before its color turns to yellow/ orange (the change in color of the vitamin C products indicates that the ascorbic acid has oxidized and is no longer very effective.