Retinol, Retinal, HPR or Bakuchiol? When to Use Which (and When to Skip)

Retinoids are the overachievers of anti-ageing skincare. They're backed by decades of research, adored by dermatologists, and occasionally responsible for a week of flaky, grumpy skin. The family has grown a lot, so let's sort out who's who and, just as important, when to use each one.

The family tree in one sentence

Skin converts retinol → retinaldehyde (retinal) → retinoic acid, and retinoic acid is the form that actually "talks" to skin cells. A 2023 review in Biomolecules explains this nicely: retinol needs a higher concentration to match retinoic acid, but it's gentler (Quan, 2023). The fewer steps an ingredient is from retinoic acid, the more directly it tends to work, and the more careful you have to be.

Meet the family

• Retinol: the classic. Two conversion steps away. Huge research base and moderate strength. It's fussy about light and air, so it's often supplied encapsulated, like Retinol, Encapsulated 10%.
• Retinal (retinaldehyde): the one-step shortcut. Only one conversion away from retinoic acid (Cosmetics, 2025), so it's used at much lower levels. It's even more light-sensitive than retinol.
• Hydroxypinacolone Retinoate (HPR): the direct messenger. An ester of retinoic acid that binds retinoid receptors without needing conversion, and is generally reported to be less irritating (Pharmaceutics, 2026).
• Bakuchiol: the plant-based alternative. Not a retinoid at all. It comes from the babchi plant. In a 12-week randomised trial with 44 people, 0.5% bakuchiol matched 0.5% retinol on wrinkles and pigmentation, with less scaling and stinging (Dhaliwal et al., British Journal of Dermatology, 2019).

When to use which

• Total beginner, or sensitive skin? Start with bakuchiol or HPR.
• Want the classic with the most research? Retinol, ideally encapsulated.
• Experienced user who wants to step up? Retinal, at low levels.
• Want a retinoid-style product for daytime? Bakuchiol is the most daytime-friendly, but daily sunscreen is non-negotiable either way.

When to use it: the routine timing

• Night, not day. Retinoids break down in light, and newly renewed skin is more sun-sensitive.
• Go slow. Two or three nights a week for the first few weeks, then build up.
• Buffer if needed. Apply over a simple moisturiser, or mix it into one. A barrier-friendly base with ceramides and panthenol helps a lot.
• Don't stack with strong acids on the same night while your skin is adjusting.

When to skip it

• Pregnancy, trying to conceive or breastfeeding: retinoid teratogenicity is well documented, and the EU's scientific committee took pregnancy exposure into account when setting limits (SCCS opinion on vitamin A). DermNet also notes that some topical retinoids are contraindicated in pregnancy (DermNet). Speak to your doctor. Bakuchiol is often suggested as the alternative, but check with them first.
• Irritated, sunburned or freshly waxed skin, or right before a big event if you're new to retinoids.

For formulators: know the rules

In the EU, Commission Regulation (EU) 2024/996 caps retinol, retinyl acetate and retinyl palmitate at 0.3% retinol equivalent in face and hand products and 0.05% in body lotions. Products also need the label "Contains Vitamin A. Consider your daily intake before use." New products must comply from 1 November 2025, and everything on shelves from 1 May 2027 (EUR-Lex). Other markets have their own rules, so always check your destination.

• Retinoids go in the oil phase at cool-down, protected from light and, ideally, air. See the retinol, retinal and HPR entries in our Ingredient Dictionary for use levels and handling.
• Add an antioxidant like Tocopherol and use opaque, airless packaging.
• Encapsulated and complexed forms can improve stability and comfort. Compare options in Delivery Systems & Encapsulation.

Explore the whole family in Anti-Ageing & Longevity, and remember: the best retinoid is the one you can use consistently without wrecking your barrier.

Education only, not medical advice.