Obagi Professional-C 10%, 15% or 20%: which vitamin C serum is right for you?
Written by Dr Elif Benar, dermatologist at Dr Elif Clinic, 54 Harley Street, London. Our doctors use and recommend these products in clinic every day.
Obagi Professional-C is one of the vitamin C serums we recommend most often in clinic. It uses L-ascorbic acid, the most studied form of vitamin C, and comes in three strengths. Patients often ask which one to buy. The short answer: the right strength depends on your skin type and how used your skin is to vitamin C.
What vitamin C does for the skin
- It is an antioxidant that helps protect the skin from daily environmental stress such as UV and pollution.
- It helps brighten a dull complexion and improve the look of uneven tone.
- It supports the skin's own collagen, which helps the skin look firmer over time.
Vitamin C works best in the morning, under your sunscreen. It does not replace SPF, but the two work well together.
The three strengths compared
| Serum | Best for |
|---|---|
| Professional-C 10% | First-time vitamin C users, sensitive or drier skin |
| Professional-C 15% | Most skin types; the strength we recommend most often |
| Professional-C 20% | Normal to oily skin that already tolerates vitamin C well |
A higher percentage is not automatically better. If a serum stings or makes your skin red, a lower strength used every day will give you more benefit than a stronger one you can only use occasionally.
How to use it
- Cleanse in the morning, for example with Obagi Nu-Derm Gentle Cleanser.
- Apply 5 drops of Professional-C to dry skin on the face and neck.
- Follow with a moisturiser such as Obagi Hydrate.
- Finish with a broad-spectrum SPF 30 or higher, such as Obagi Sun Shield Mineral SPF 50.
Professional-C 15% and 20% are also available as kits: the Brightening Duo 15% and the Brightening Duo 20%.
Frequently asked questions
Can I use Obagi Professional-C with retinol?
Yes. Use vitamin C in the morning and retinol in the evening. This is a common routine and keeps irritation low.
Why does my vitamin C serum tingle?
A mild tingle in the first seconds is common with L-ascorbic acid. If it burns, or your skin stays red, switch to a lower strength or use it every other day.
How long does a bottle last?
Used once a day, a 30ml bottle usually lasts around two to three months.
When will I see results?
Most people notice a brighter, more even look after 6 to 12 weeks of daily use together with sunscreen.
Need help choosing?
Every skin is different. If you are unsure which product suits you, book a consultation at Dr Elif Clinic on Harley Street, or send us a message through our contact page. This article is general information and is not a substitute for personal medical advice.