Hello, I recommend you to check the ingredients on the web page, which will clearly explain the nature of use. For example,
Pumpkin Renew™ Copy the details of use from the website as follows
Usage: For nourishing products. Any skin type Method of application: Mix in water (water-phase). Heat above 60°C must be avoided. Formula should have a pH in the range of 4.5-7.0. Usage rate: 1-10% (3-5% recommended for use. Work every day and 10% for
ผลัดเซลล์ผิว only occasionally) Product characteristics: Dark yellow liquid, pH in the range of 4.5-7.5 ka. Solubility: soluble in water