What Is 7-Dehydrocholesterol?
7-Dehydrocholesterol is a naturally occurring lipid also known by its chemical name cholesta-5,7-dien-3(beta)-ol. It sits one step before vitamin D in the body’s own chemistry and is found in human skin, fish oils and lanolin from sheep’s wool. Cosmetic chemists became interested in it in the mid-20th century when they noticed its close similarity to the skin’s own barrier lipids, which suggested it could help formulas feel more skin-compatible.
Commercially, most 7-Dehydrocholesterol used in cosmetics is extracted from purified lanolin. The raw wool grease is cleaned, then the cholesterol fraction is separated and further refined to yield 7-Dehydrocholesterol in crystalline form. Modern methods may also use plant sterols that undergo a series of controlled reactions to reach the same structure, giving brands a choice between animal-derived or plant-derived supply chains.
You will usually find this ingredient in products where a stable, skin-like emulsion is key: rich moisturizers, night creams, anti-aging serums, barrier repair masks and specialty treatments designed for dry or fragile skin.
7-Dehydrocholesterol’s Cosmetic Benefits/Uses
Formulators choose 7-Dehydrocholesterol for several practical reasons
- Emulsion stabilising: It helps oil and water phases stay blended, so creams resist separating in the jar and spread evenly on the skin
- Skin conditioning: Its lipid structure mimics natural skin oils, adding a silky finish and supporting the skin barrier, which can reduce dryness and tightness
- Viscosity controlling: By thickening the oil phase it gives lotions a plush, cushiony texture without making them feel greasy
Who Can Use 7-Dehydrocholesterol
Most skin types, especially dry, mature or compromised skin, tend to tolerate 7-Dehydrocholesterol well thanks to its skin-like lipid profile that helps reinforce the barrier and lock in moisture. Combination skin usually finds it comfortable in balanced formulas. Very oily or easily congested skin might feel it is a bit rich if the overall product is heavy in oils, so lighter textures are preferable in that case.
Vegans and vegetarians should check a brand’s sourcing statement because the ingredient is often obtained from lanolin, an animal-derived material. Some suppliers now create a plant-derived version from hardened plant sterols, so products that specify a vegan supply chain are available.
No specific warnings link 7-Dehydrocholesterol to pregnancy or breastfeeding issues when used topically in cosmetic amounts. Still, this is not medical advice and anyone who is pregnant or nursing should have their healthcare provider review any skincare they plan to use just to be safe.
The ingredient itself is not known to cause photosensitivity. It can break down in strong UV light which is why many formulas house it in opaque or air-tight packaging yet this breakdown does not translate into the user becoming more sun sensitive.
Potential Side Effects/Adverse Reactions
Responses to any ingredient differ from person to person. The points below outline potential side effects yet they are uncommon when 7-Dehydrocholesterol is formulated and preserved properly.
- Mild skin irritation – very sensitive skin may notice fleeting redness or stinging, usually due to other actives or preservatives in the formula rather than the sterol itself
- Allergic response to residual lanolin compounds – rare but possible if traces remain from animal-derived sourcing, leading to itching or small bumps
- Breakouts or pore clogging – may occur on skin that is already prone to acne if the overall product is heavy or occlusive
- Product oxidation – if a jar is left open the sterol can oxidize, and the degraded product could trigger irritation or an off smell
If any unwanted reaction develops stop using the product and seek advice from a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 2/5
7-Dehydrocholesterol is a waxy sterol that sits in the same family as cholesterol, which the skin naturally produces. Its molecular size lets it blend into the outer skin layers rather than pool inside pores, so the clogging risk is low to moderate. Formulas that pair it with heavy butters or high levels of waxes can raise the risk, which is why it receives a cautious 2 instead of a full non-comedogenic 0.
Most people prone to acne can use it without trouble, especially in lightweight or balanced emulsions, but very oily or highly congested skin should still keep an eye on how a product feels after repeated use.
As with any emollient, the comedogenic impact also depends on the complete formula, how much of the ingredient is present and individual skin chemistry.
Summary
7-Dehydrocholesterol works as an emulsion stabiliser, a skin-conditioning lipid and a viscosity controller. Its sterol structure slides between oil and water phases to keep creams uniform, strengthens the skin barrier by mimicking natural lipids which reduces dryness and tightness, then adds a plush thickness that makes products feel cushioning without leaving a greasy film.
It is more of a specialty ingredient than a household name, showing up mostly in barrier repair moisturisers, night creams and high-end treatments rather than drugstore staples. Brands that want a skin-identical story or a rich sensorial finish reach for it, while others stick to simpler fatty alcohols or plant oils.
Safety profiles and decades of cosmetic use point to a very low risk of irritation or toxicity. Rare issues come from residual lanolin in animal-derived batches or from using an oxidised, poorly preserved formula. As with any new skincare product it is smart to patch test first so you can confirm personal tolerance before applying it widely.