Panthenol (Provitamin B5) — From Post-Surgical Wounds to Everyday Creams. The Science Behind D-Panthenol
In the skin, D-panthenol converts to pantothenic acid and cuts TEWL by up to 30%. Effective range: 2-5%. Explore the studies and post-procedure use.
On the INCI list it appears as Panthenol — in its active form this is D-panthenol, the alcohol analogue of pantothenic acid, otherwise known as vitamin B5. It has featured in Bayer's products since 1944, when the company launched the Bepanthen ointment for wound care. Eighty years on, the ingredient still appears in dermatological care standards following laser treatments, chemical peels and tattoos. So what do we actually know about how it works in light of modern research?
The biochemistry of conversion: from provitamin to coenzyme A
D-panthenol is biologically inactive on its own. Once it penetrates the epidermis, it undergoes enzymatic oxidation into D-pantothenic acid (vitamin B5), which is a precursor of coenzyme A (CoA). Coenzyme A is involved in more than 70 metabolic reactions in skin cells, including the synthesis of barrier lipids, fatty-acid metabolism and tissue repair following damage.
This distinction is crucial: pantothenic acid itself penetrates poorly through the skin because of its ionic charge. As a neutral molecule, D-panthenol crosses the stratum corneum far more efficiently, with conversion taking place only once it reaches the living layers of the epidermis.
Effective concentrations — what do the clinical studies say?
A systematic review by Proksch and Nissen (2002), published in Skin Pharmacology and Applied Skin Physiology, indicates that:
- 1% — the minimum concentration that delivers measurable hydration (reduced TEWL).
- 2–5% — the optimal range in most studies. At 5%, transepidermal water loss (TEWL) was reduced by as much as 25–30%.
- Above 5% — no evidence of additional benefits proportional to the concentration, while the viscosity of the formula increases.
In the CosIng register of the European Commission, panthenol is listed with the functions: hair conditioning, skin conditioning and skin protecting. Regulation 1223/2009 sets no concentration limit — it is one of the best-tolerated ingredients, with no known cases of contact sensitisation at cosmetic concentrations.
TEWL — why does this measure matter so much?
Transepidermal water loss (TEWL) is a measure of the skin barrier's integrity. Healthy skin loses roughly 5–10 g/m²/h. After damage — from a peel, a laser or a burn — this value can rise as much as threefold. Panthenol does not work like occlusive petroleum jelly, physically blocking water in. Instead, it stimulates lipid synthesis in the stratum corneum, rebuilding the barrier from within.
This is a fundamentally different mechanism from that of glycerin (a humectant) or petroleum jelly (an occlusive emollient). Panthenol acts on a metabolic rather than a surface level — which is why its effects build up over time with continued use rather than disappearing once the product is rinsed off.
The history of Bepanthen — from nappies to aesthetic dermatology
When Bayer AG (at the time part of IG Farben) developed the Bepanthen formula in 1944, the goal was to protect babies' skin from nappy rash. The ointment contained 5% D-panthenol in a lanolin base. For decades the product remained the preserve of paediatrics and surgery (the healing of post-surgical wounds).
The breakthrough came in the 1990s, when aesthetic dermatology clinics began documenting faster healing after ablative procedures (CO₂ laser, dermabrasion) in patients using 5% panthenol. Ebner et al. (2002) published a randomised, double-blind trial that demonstrated a statistically significant acceleration of re-epithelialisation (the regeneration of the epidermis) in the panthenol group compared with placebo.
Post-procedure use — specific protocols
Current guidelines from dermatological societies recommend panthenol for post-procedure care in the following situations:
- After chemical peels (glycolic, TCA) — from day 2, 3–4 times a day, using a 5% product.
- After laser treatments (fractional CO₂, IPL) — immediately after the procedure, as the first layer beneath an occlusive dressing.
- After microneedling (dermapen) — 24–48 hours after the procedure, using a cream with panthenol + hyaluronic acid.
- After a tattoo — as an alternative to petroleum jelly, which can cause maceration; panthenol does not block the skin's gas exchange.
What to look for when choosing a product?
On the market you will find products with DL-panthenol (a racemic mixture) and D-panthenol (the pure isomer). Only the D form is biologically active — the L isomer does not undergo enzymatic conversion into vitamin B5. On the INCI list both forms are written identically as "Panthenol", which makes them hard to tell apart. Premium manufacturers usually state the form in their technical documentation, but not on the packaging.
The position on the INCI list will give you a rough idea of the concentration. If panthenol appears among the first five ingredients (after water and emulsifiers), you are probably dealing with a concentration of 2%+. If it sits well after the fragrance composition, it is more likely a marketing token.
Learn to interpret INCI lists for yourself — our guide to reading product compositions shows you how to tell an active ingredient apart from a marketing add-on.
FAQ
D-panthenol is the biologically active isomer that converts into vitamin B5 in the skin. DL-panthenol is a racemic mixture in which only half of the molecules (the D form) are active. On the INCI list both forms are written as 'Panthenol', so the difference can only be verified in the manufacturer's documentation.
No — they work by different mechanisms. Hyaluronic acid is a humectant that binds water on the surface and within the epidermis. Panthenol stimulates the synthesis of barrier lipids, reducing water loss from within. The best results come from combining the two.
Clinical studies point to the 2–5% range as optimal. At 5%, TEWL drops by 25–30%. Concentrations below 1% may not deliver measurable skincare effects, although they are still safe.
Yes — it is recommended as an alternative to petroleum jelly. Panthenol does not form a tight occlusive layer, so it does not block gas exchange, while at the same time accelerating re-epithelialisation. Use 5% panthenol products free from dyes and fragrance.
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