Top Questions on Obagi Vitamin C Serums, Answered

So you've finally decided you need a vitamin C serum---congratulations, you are one step closer to achieving a brighter, more youthful complexion. You've read all about the little-known benefits of this powerful antioxidant and even found out that Obagi Medical, one of the most renowned professional skin care lines (and one of the most dedicated to ensuring their products are tested on all skin tones), offers some of the best vitamin C serums out there. Still, you find yourself confused. What is L-ascorbic acid and what do those percentages mean?

Lucky for you, we're here to demystify the science behind vitamin C and Obagi's Professional-C Serum line. Here, we chatted with the experts at Obagi to answer seven of the most frequently asked questions about this line.

Question#1: What result can I expect from a vitamin C serum?

Answer: Vitamin C is essential for a healthy body, and therefore essential for healthy skin and hair. It's a potent antioxidant that can neutralize free radicals, such as those found in environmental pollutants and after exposure to ultraviolet radiation. A vitamin C serum can do various wonders for your skin. Among the most noticeable benefits are the following:

Even skin tone; diminished dark spots
Reduced appearance of fine lines and wrinkles
Brighter skin overall

Question#2: Why does Obagi prefer L-ascorbic acid over other forms?

Answer: Not all forms of vitamin C are created equal, and there are many derivatives on the market. Obagi uses L-ascorbic acid because it is known to be the most bioavailable (most absorbed by your skin) and thus most efficacious form.

Question#3: Why do Obagi Vitamin C serums come in different concentrations (10%, 15% and 20%)? What's the difference and who should use which?

Answer: There are three percentages of L-ascorbic acid available in the Obagi Professional-C product line. A higher concentration isn't necessarily better than a lower concentration; the difference is in intended use.

- Professional-C Serum 10%
  - Concentrated formula recommended for dry, irritated or sensitive skin
- Professional-C Serum 15%
  - High-performance serum developed for most skin types
- Professional-C Serum 20%
  - Highest concentrated serum best suited for normal to oily skin

Question#4: How should we use Obagi's vitamin C serum for best results?

Answer: Obagi vitamin C should be used in the morning and/or evening after cleansing, and possibly exfoliating and toning the skin in a more comprehensive routine. Apply five to seven drops to the face, neck and chest using fingertips. Always apply Obagi vitamin C to cleansed skin before makeup and sunscreen application. Here's how to incorporate it into your skin care routine:

Step 1: Cleanser or scrub
Step 2: Exfoliator (this step might be included in your cleanser if it’s also exfoliating)
Step 3: Toner
Step 4: Serum, such as the Obagi Professional-C Serum products (AM/PM, or AM only if using a retinoid at night)
Step 5: Retinol (PM only)
Step 6: Moisturizer and Eye Cream
Step 7: Sunscreen (AM only)
Step 8: Makeup

Question#5: What ingredients work best with vitamin C?

Answer: Obagi recommends using a broad-spectrum sunscreen in conjunction with a vitamin C product like the Professional-C serums because the protection from the sunscreen will work in tandem with the antioxidant benefits derived from vitamin C. Also, using a vitamin C exfoliator will help enhance the benefits by promoting deeper penetration for absorption.

If using ELASTIderm eye cream with your L-ascorbic acid products, apply ELASTIderm to the eye area and Professional-C serum to surrounding skin for best results.

Lastly, when used in combination with retinol, apply vitamin C in the morning and retinol at night.

Question#6: Can you get too much vitamin C? What happens when you apply too much, or too strong a concentration?

Answer: L-ascorbic acid is appropriate for all skin types. We do recommend choosing the appropriate concentration to meet your skin’s specific needs.

Our Pro-C serum 10% is designed for dry, irritated or sensitive skin, Pro-C Serum 15% is designed for combination skin/most skin types and Pro-C serum 20% is best suited for normal-to-oily skin.

Question#7: How should we store our vitamin C serums to maintain potency?

Answer: The shelf life of L-ascorbic acid is typically three to four months after opening, but can be shorter if exposed to light, air or heat for long periods of time. Keep the container securely closed when not in use. Storing your Obagi Professional-C Serum in a cool, dark area, such as a refrigerator (not freezer), may help to prolong its shelf life.