This discolouration can happen with all kinds of colorful polyphenols we encounter in botanical ingredients, like anthocyanidins and anthocyanins in strawberry extract, the procyanidins in green tea extract, and proanthocyanidins in grapeseed extract. They offer so many benefits to our skin, like reducing inflammation and water retention, helping stabilize collagen and elastin, and acting as anti-oxidants, so we want to include them, but the color can both change our product and stain our skin. 

Clearly these compounds can offer wonderful things to a skin care product, but we must be careful to stay within the “safe as used” and suggested usage rates to avoid discoloration, ruined products, and potential harm. Sea buckthorn oil is a fabulous moisturizer and skin softener that can act as a wound healer, anti-inflammatory, and anti-microbial. Unfortunately, all those carotenoids can turn your snow white body butter into a luscious skin custard at even low levels, which could stain your skin quite easily. Before using a brightly colored extract or oil in a face mask, lotion, hair product, eye gel, or other leave on product, do a patch test for a few days to see if it’ll stain your skin at the suggested usage rate. 

If you still want all that skin loving anti-inflammatory and free radical scavenging power of resveratrol or turmeric, what can you do? Start with a botanical extract from a bath & body ingredient supplier. These are standardized to include the good things you want – say ascorbic acid in rosehip or salicin in white willow bark – so you can decide exactly how much you want to use. If I want to make sure I’m getting 0.1 grams of caffeine in my green tea, aloe, and squalane lotion, I’ll make sure that I use 1 gram of powdered green tea extract that has standardized 10% caffeine. 

Powdered extracts are processed to be more water soluble, but can still contribute a bright or intense color to a product. Liquid botanical extracts tend to be less brightly colored or even transparent. We generally use them at higher rates as they can be less concentrated than the powders. Powdered green tea extract tends to have a suggested usage rate at 0.5%, while the liquid could be suggested at 5% to 10%. Check to see if the version you like is oil or water soluble to ensure it works with your recipe. 

Consider buying just the compound you want in a botanical ingredient, like caffeine, resveratrol, or salicylic acid instead of the complete version. These extracts are generally white powders or clear liquids. You’ll probably pay more as they can be considered cosmeceuticals rather than extracts, but you’ll use far less at levels as low as 0.05% to 0.1%. 

If you really love the idea of using bright botanical ingredients in your products, consider a few things before you make that recipe. The first is to consider making more rinse off products, like facial cleansers, shampoos, scrubs, or body washes, or in a very diluted state like toners or skin sprays. If you’re using oils, dilute them with other oils rather than using them neat or use very small amounts in lotions or anhydrous products. 

Use only the suggested usage rate and no more. Measure all your recipes by weight to avoid all those icky messes of undissolved powders, failed lotions, and poorly preserved products. Very often recipes from social media sites measure by volume, which is not only inaccurate, but messy as you’ll have to clean all those small spoons and cups after a day in your workshop. You can’t convert from volume to weight easily, so consider finding a new recipe if the one you have isn’t weighed. Or learn how to convert using the ingredient’s specific density, which is a whole lot of math! 

Be aware that the intensity of the color of an ingredient depends upon so many things that can’t be standardized, like the climate, location, and season in which it’s harvested, so the lotion that was okay with 10% rosehip oil last month might stain at 8% this month as it contains more carotenoids. Keep good records and take pictures of your ingredients if you need a reference.

Botanical ingredients are notoriously difficult to preserve, so when using even the best quality powders and liquids from our suppliers, make sure you’re using the maximum suggested usage level of a broad spectrum preservative. I generally use 0.5% liquid Germall plus in my products, but I also like Germaben II or Phenonip at 1% or Optiphen Plus at up to 1.5% for my more botanical heavy products, like toners and eye gels. 

And if you choose to use kitchen ingredients, like brewed tea or freshly grated turmeric, assume those products are one-offs and cannot be stored in or out of the fridge, even with good preservation.