Why Both Concentration and Delivery Matter
Vitamin A is one of the most studied actives in skincare, with decades of clinical literature behind it. But the translation from research to product is complicated by two variables that are often treated as separate questions: how much vitamin A a formula contains, and how that vitamin A reaches the skin cells that can use it.
The Concentration Problem
Most over-the-counter retinol products sit between 0.025% and 0.3%. At the lower end, the dose is subthreshold for most skin types, meaning it may cause some initial sensitivity without producing the cellular changes that make vitamin A clinically useful. At the higher end, conventional retinol causes sufficient irritation that many people discontinue use before results appear.
Prescription tretinoin sidesteps this by using retinoic acid directly, bypassing the enzymatic conversion steps that retinol requires. The tradeoff is a much higher irritation profile that limits who can use it and at what frequency.
Where Delivery Format Changes the Calculation
Encapsulated vitamin A, released over 8 to 12 hours, addresses the concentration-irritation tradeoff differently. Because the dose reaches the skin gradually rather than all at once, higher concentrations become tolerable. Professional-grade skincare using 1% encapsulated vitamin A can deliver a clinically relevant dose twice daily without the flaking and sensitivity that the same concentration would produce in a conventional formulation.
The slow-release mechanism also extends the window of activity. Vitamin A applied in a conventional format is largely metabolised within a few hours. An encapsulated form that releases across 8 to 12 hours maintains active concentration in the skin for longer, which is relevant to how the ingredient drives cell turnover and collagen synthesis.
Practical Implications for Choosing a Formula
When comparing vitamin A products, concentration alone is not sufficient information. A 1% retinol in a conventional base and a 1% encapsulated retinaldehyde deliver very different amounts of active to the target cells, at very different irritation profiles. The delivery system is at least as important as the percentage on the label.
For anyone who has abandoned retinol due to irritation, encapsulated formats are worth reconsidering before concluding that vitamin A does not suit their skin.
Mathew Hicks is a world-renowned author and expert in the field of business and finance. He has written multiple books and articles on the subject and has been featured in numerous publications. His expertise has been sought by leading financial institutions around the world.