This sheer, creamy formula comes in a range of six strengths of retinaldehyde, from 0.01% (for sensitive skin) all the way up to 0.24% (for longtime users). Our panelists tried Medik8 Crystal Retinal 3, the 0.03% concentration recommended for new users by the dermatologists we spoke with. Testers loved its superior texture and absorption, but they were divided on the tube packaging.
A fast-acting over-the-counter form of vitamin A is the star ingredient. Unlike prescription-strength vitamin A (retinoic acid), which directly interacts with skin to hasten cell renewal, stimulate collagen production, and curtail inflammation and oiliness, OTC derivatives must be activated by the body’s natural enzymes. Retinaldehyde, the derivative in Crystal Retinal 3, needs only one step to convert to retinoic acid, and it has been linked to faster, more visible results when compared with retinol (which requires two steps to convert).
Available in a range of strengths, this product contains an encapsulated retinal. We tested Medik8 Crystal Retinal 3. But this serum comes in a range of strengths — from 0.01% (for newbies with the most sensitive skin) to 0.24% (for longtime users), so you can slowly increase the concentration to match your skin’s needs. Plus, this formula contains an encapsulated retinal: A lipid encases the retinaldehyde to help regulate the speed of its absorption, so it’s less apt to irritate skin. Although we can’t directly link this to the encapsulation, a few of our panelists did notice that Medik8’s sheer serum didn’t trigger sensitivity at all.
Its smooth formula absorbs beautifully. Every tester who tried the Medik8 Crystal Retinal 3 specifically praised how nicely it spreads into skin: Fresh out of the pump, it looks like lotion, but then it massages into a sheer, silky layer. One tester noted that after she applied it, her face “felt a teeny bit dry — but not in a bad way.” While comparing serums, panelists said they generally much preferred the Medik8 serum’s creamier spreadability to more-watery, drippy options, like Trader Joe’s Retinol Night Serum.
It smells good. Across the entire retinoid category, testers consistently flagged unpleasant fragrances (especially with the L’Oréal Paris drops, despite this serum’s other excellent attributes). The Medik8 serum, which has no added synthetic fragrance, was lauded for its nice, subtle aroma.
Flaws but not dealbreakers
- Medik8 Crystal Retinal 3 is expensive. Among the prices of the 12 contenders our panelists tested, this $65 serum trailed only Shani Darden Retinol Reform Treatment Serum (about $90), SkinMedica Retinol Complex 1.0 (about $100), and SkinMedica Retinol Complex 0.5 ($80). Moreover, the cost creeps up along with the concentration level: Crystal Retinal 6 will run you $85, and Crystal Retinal 10 is about $110.
- The hybrid packaging was polarizing. The silver plastic tube is topped with a metal pump and a plastic cap, and some testers loved it because they said it’s tidy and easy to place upright on a medicine-cabinet shelf. But another tester had to repeatedly press the pump to release even a small squirt of serum.
