Vitamin C acts as an effective antioxidant, brightens the skin tone, and reduces visible signs of aging. Ascorbyl tetraisopalmitate is an oil-soluble and extremely stable derivative of vitamin C. It is provided in this oil format formula in combination with vitamin F, also known as essential fatty acids. Aside from the general benefits of pure vitamin C, ascorbyl tetraisopalmiate has been shown to offer enhanced skin brightening benefits.
The Ordinary's portfolio of Vitamin C includes the following formulations:

Vitamin C Suspension 30% in Silicone
Vitamin C Suspension 23% + HA Spheres 2%
Ascorbyl Glucoside Solution 12%
Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F
Magnesium Ascorbyl Phosphate 10%
Ascorbic Acid 8% + Alpha Arbutin 2%
Ethylated Ascorbic Acid 15% Solution
100% L-Ascorbic Acid Powder

Topical Vitamin C offers a wide array of benefits to the skin. However, many forms of Vitamin C and many more formulations of Vitamin C are available commercially with a potential to confuse the audience. We have developed a guide that offers guidance on the formulations of Vitamin C offered under The Ordinary range. It also offers education on Vitamin C itself and on the differences between formulations of Vitamin C at large. Note: Supplied in UV-protective packaging.
How to use 

Apply a few drops to the entire face in the AM and/or PM. If irritation occurs, cease use and consult a physician. Use only as directed on unbroken skin. Patch testing prior to use is advised. Keep out of reach of children.

Patch tests are an easy way to help predict if you may experience a negative initial reaction to a new product. It is recommended to perform a patch test before incorporating any new product into your regimen. We have outlined a general method for conducting your own patch test below based on the type of product.

• Apply a small amount of the product onto a clean area of skin on the upper forearm.
• Keep the area dry.
• If the product has a specified duration of use, rinse off after this time has elapsed. Otherwise rinse off after 24 hours.
• If any redness, burning, itching, blistering or irritation is observed at any time throughout the test, do not use the product.