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Green tea
Just a tip. For those of you interested in using green tea extract in skin preparations, I have found that a 0.2% concentration, when the cream is adjusted to pH 6, produces a nice beige-pink colour close to caucasian skin tones. It’s a low cost active ingredient and there is quite a bit of info on the Web, for instance:
“Dr. Hsu thinks that EGCG may be a fountain of youth for skin cells. When exposed to EGCG, the old cells found in the upper layers of the epidermis appear to start dividing again. They make DNA and produce more energy. They are reactivated. In addition, the researchers found that EGCG accelerates the differentiation process among new cells.
Combining these effects of EGCG on skin cells in different layers of the epidermis, there may be potential benefits for skin conditions as diverse as aphthous ulcers, psoriasis, rosacea, wrinkles and wounds.” -
21 Replies
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Very interesting Mr. Belassi. Thank you! for sharing this. Javier
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Interesting. Thanks for posting.
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I’ve been using Teavigo Green Tea Extract (95% EGCG) at 0.1% in a variety of products. Yes, it is a light pink color! To prevent (prolong) Green Tea Extract oxidation (it will turn darker brown over time), use 0.5% Citric Acid and 0.5% Hydrolysed Wheat Protein.
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Thanks for the useful info, I had noticed it darkening a bit over time. I’ll try that because I have both of those.
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One other point … EGCG is generally more stable at lower pH levels. Instead of adjusting your pH to 6.0, try going in the opposite direction, down to about 4.0. The optimal pH range for EGCG stability is 4.0 to 6.0 and better at the lower end of the range. Since the pH of skin is approximately 4.7, this would give your creams a better pH balance for skin. Finally, at pH 6.0 you’re pushing on the upper boundary on the effectiveness of most preservatives, so you would also benefit on preservation. Just a thought.
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Thanks for that. I suspect though, that if I go lower in pH I will have emulsion stability problems because, frankly, the emulsion would not be stable without the carbomer’s effect, and the carbomer needs to be not too acidic or it won’t work properly. I’m not worried about the preservative because it’s a parabens system, and at 0.5% we’re already past 4 years on the long term shelf test.
I designed the product before I knew enough emulsion chemistry and I can clearly see that it’s only the carbomer that keeps it stable; but it is a really popular product so I won’t mess with the formula just because it’s theoretically unstable (grin). -
Understood. If you do want to formulate with Carbomer at lower pH levels, Carbopol Ultrez 30 gels at pH 4.0.
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I keep 940, Ultrez-20 and Aqua SF-2 in stock, but when I tried substituting Ultrez-20, it changed the feel of the product in a not-nice way, unfortunately. 940 is a pain to use… but gives a perfect sensorial.
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Hi!
I am preparing a sunscreen containing green tea extract and ZnO. My question is, how do I adjust the pH? Cause, ZnO needs a pH between 7.1 to 7.5 but green tea extract (with EGCG) would require a lower pH. Any ideas? Please do let me know!
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When you’re formulating with ingredients that have conflicting pH requirements for stability, you’re best only option is to try shooting the gap and see what happens … or, chose one ingredient or the other, but not both. In this case, if you’re using a Green Tea Extract in water/glycerin, you probably won’t have a problem at a higher pH. If you’re using a Green Tea Powder like Teavigo, it will turn brown quite quickly.
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What is the purpose of the green tea in this product?
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Tea is an indicator. The colour of the product will reflect the pH.
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I don’t think that is a good reason for including what is, seemingly, fairy dust in a functional product.
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Well, green tea does have an effect on reducing UV-induced cell damage. As does pine bark extract. Similar mechanism perhaps. So not a bad thing to include.
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Hi johnb, why do you consider green tea as fairy dust. I thought it contains lots of antioxidants?
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@Pete - You would be hard pressed to show any effect when delivered from a standard cosmetic product.
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This thread dates back to 2014 where the main subject was green tea and its various attributes - fine, I have no problem with that howver, the thread has just been hi-jacked by @Rutuja who wishes to include green tea in a functional product, namely a sunscreen.
This inclusion is, apparently causing concern over pH adjustment/control. My own concern is why is green tea included in the formulation. It doesn’t have a real function in a sunscreen - hence my use of the term “fairy dust”.
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Hi guys, thank you so much for your response! Really helpful
Well, I’m only a student and was given this topic by my professor to work on.A lot of botanical variety including green tea, prickly ash, etc are gaining interest due to studies which hint at their UVA targetting abilities to combat skin cancer and photo aging.
@MarkBroussard
sorry for the delayed reply,but thanks a lot for your tip! Actually works for me as an amature -
Thanks for the clarification. I see now
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I wanted to re-open this again, for @MarkBroussard or @Belassi or anyone else still using this EGCG (or similar) extract.
The 0.5% citric acid has not been enough to prolong discoloration time; I typically notice the change in color after about three weeks, using 1% EGCG. Do you think this hydrolyzed protein extract will make all the difference, or is there perhaps another ingredient I should try? I am also going to try Miron (violet) glass, which should help, but I would prefer not to have to go to airless (plastic) packaging.
Thank you.
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These extracts tend not to be stable. At least in my experience. I wasted an awful lot of time trying to extend shelf life with little success.
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