Grape seed extract ratio to use as natural preservative in moisturizer?

The typical recommended usage level of grape seed extract as a natural preservative in cosmetics and personal care products is between 0.1% and 1%.

To use grape seed extract as a natural preservative in a moisturizer, you can follow these steps:

- Calculate the amount of grape seed extract needed based on the desired concentration and the total weight of the moisturizer you are making. For example, if you want to add grape seed extract at a concentration of 0.5% and you are making 100 grams of moisturizer, you will need 0.5 grams (or 500 milligrams) of grape seed extract.

- Weigh out the required amount of grape seed extract using a digital scale.

- Add the grape seed extract to the moisturizer base.

- Stir or mix thoroughly to ensure that the grape seed extract is evenly distributed.

It's important to note that the effectiveness of grape seed extract as a natural preservative may vary depending on the specific formula of your moisturizer and the storage conditions. To ensure product stability and safety, it's always a good idea to conduct preservative efficacy testing before using grape seed extract or any other natural preservative in your cosmetic formulations.