Obagi Professional-C Serum 15% Review

Obagi Professional-C Serum 15% is the middle strength in Obagi's three-strength Professional-C vitamin C range, sitting between the entry-level 10% and the maximum-strength 20%. It's a 30ml fluid serum built around 15% L-Ascorbic Acid — the purest, most researched form of vitamin C used in skincare — for anyone who's tolerated a lower-strength vitamin C serum before and wants more from the same step in their routine.

What is Obagi Professional-C Serum 15%?

This is a fast-absorbing, lightweight fluid dispensed from a glass bottle with a precision dropper, built around a single headline active: 15% L-Ascorbic Acid. It's the mid-point of Obagi's Professional-C line-up, positioned above Professional-C 10% for skin that's already comfortable with daily vitamin C, and below Professional-C 20% for anyone not yet ready for the strongest version. Obagi's own product data lists this as suited to normal to combination skin specifically, though the wider Professional-C skin-type listing across the range also covers dry, oily, mature and rough skin.

One formulation detail worth flagging: unlike Professional-C 20%, which lists Sodium Hyaluronate alongside the vitamin C on its current product record, the 15% strength doesn't carry a confirmed secondary hydrating active in the same way. That's not necessarily a downside — it just means the formula here is built to be a straightforward, single-active vitamin C step rather than a combination serum.

Key ingredients

• L-Ascorbic Acid (15%) — the sole headline active, an antioxidant that helps protect skin against everyday environmental stressors and supports a brighter, more even-looking complexion with regular use

DATA GAP: beyond the core vitamin C active, Obagi's published product data for this strength doesn't confirm a specific secondary or supporting ingredient list, so we haven't invented one here.

Who it's for

• Vitamin C users who've already used Professional-C 10% (or a comparable lower-strength serum) without irritation and want a noticeable step up
• Anyone wanting a daily antioxidant serum aimed at a brighter, more even-looking complexion
• Normal, combination, dry, oily, mature or rough skin, per Obagi's Professional-C range skin-type guidance

It's a less obvious starting point for anyone who's never used a leave-on vitamin C serum before, or who knows their skin reacts easily to new actives — Professional-C 10% is Obagi's own recommended entry point for that instead.

How to use it

Per Obagi's own directions, this is an AM step: apply 5–7 drops to the face, neck and décolletage on cleansed, toned skin, then follow with moisturiser and a broad-spectrum SPF before makeup. It's intended for daily use. A mild tingling sensation on application is described as normal by Obagi, particularly when a routine is new to vitamin C, and is expected to lessen with continued use — if you're introducing vitamin C to your routine for the first time, starting on alternate days before building up to daily use is a sensible approach. The serum's colour can vary from clear to deep amber between batches; this is a normal characteristic of the antioxidant and doesn't affect how the product works. Keep the cap on tightly between uses, store away from direct light and heat, and use within 12 months of opening.

Where 15% sits: choosing between 10%, 15% and 20%

Obagi's Professional-C range uses the same active — L-ascorbic acid — across all three strengths, so the choice comes down to how much your skin is ready for rather than which one "works better". Professional-C 15% is the logical next step if Professional-C 10% has felt too mild after consistent use, without jumping all the way to Professional-C 20%, Obagi's most concentrated version. Our full Professional-C 10% vs 15% vs 20% comparison breaks down exactly what changes across the range and how to judge when it's time to move up a strength. For the wider Obagi vitamin C line-up, including where this serum fits alongside brightening-focused alternatives, see our best Obagi vitamin C serum guide and our Obagi brand overview.

Safety, sensitivity and pregnancy

A slight tingling on first use is expected and generally settles with continued use, per Obagi's own guidance; if irritation is more than mild or doesn't ease off, pause use and seek advice. Vitamin C serums are typically layered under a moisturiser and SPF rather than used alone. If you're pregnant or breastfeeding, please contact our team for advice before use.