Encyclopedia · oil or butter
Petrolatum
A refined mineral-oil-and-wax jelly that is the base of many greasy pomades; it seals and adds shine but does not enter the hair.
What it is
Petrolatum is a semi-solid mixture of saturated hydrocarbons from petroleum. It is the base of classic oil-based pomades and "grease" dressings. See styling products explained.
How it works
It forms a strongly occlusive film on skin and on the hair surface (Loden 2003). Its liquid relative, mineral oil, does not penetrate the hair fibre in electron imaging (Ruetsch 2001). It also did not reduce protein loss from combing in undamaged or damaged hair, unlike coconut oil (Rele 2003). A 2021 single-fibre study found coconut oil, not mineral oil, strengthened twisted fibres across washes (Kaushik 2021). The first two studies came from the same coconut-oil-industry group, so weigh them with that in mind.
What the studies show
- A review of 13 studies of mineral oil and wax absorption found they were mostly retained in the outer skin layer, with no evidence of systemic availability. The authors have industry links (Petry 2017).
- A review by German regulator authors found no indication of cancer in animals exposed on the skin or by mouth to highly refined mineral oils and waxes (Pirow 2019). The reviews apply to refined grades only, so "petrolatum is toxic" claims are not supported for them.
- Mineral oil sat on top of hair while coconut oil entered it (Ruetsch 2001).
- A single-arm 8-week study of 27 people reported that a non-comedogenic hair-care regimen improved facial and truncal acne in 52 to 70% of subjects. That supports the idea that hair products can contribute to acne, but it was small and uncontrolled (Rubin 2021).
How it's used in studies
Not applicable.
Side effects and safety
Pomade acne on the forehead and hairline is described for heavy greasy products (Plewig 1970). Petrolatum is hard to wash out and needs a strong cleansing step. It is flammable near an open flame.
Bottom line
Safe, cheap and strongly sealing. It is a fine occasional pomade or ends-sealing choice for coarse, dry hair. It adds nothing to hair health and can cause breakouts and buildup. We are moderately confident about safety and not about any hair benefit.
Fun facts
Mineral oil sits on top of hair while coconut oil goes inside it, according to electron imaging (Ruetsch 2001).
Studies 8
Petry T et al. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications. Toxicol Lett. 2017
Result: Mineral oils and hydrocarbon waxes were mostly retained in the stratum corneum, with no evidence of systemic availability.
Read the study ↗Pirow R et al. Mineral oil in food, cosmetic products, and in products regulated by other legislations. Crit Rev Toxicol. 2019
Result: No indication of carcinogenic effects in animals exposed dermally or orally to highly refined mineral oils and waxes.
Read the study ↗Ruetsch SB et al. SIMS investigation of penetration of coconut and mineral oils into human hair fibers. J Cosmet Sci. 2001
Tested: coconut oil vs mineral oil
Result: Coconut oil penetrated the hair fibre; mineral oil did not.
Read the study ↗Rele AS, Mohile RB. Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage. J Cosmet Sci. 2003
Tested: mineral, sunflower and coconut oil
Result: Mineral oil did not reduce protein loss from combing in either undamaged or damaged hair; coconut oil did.
Read the study ↗Kaushik V et al. Single hair fiber assessment techniques to discriminate between mineral oil and coconut oil. J Cosmet Dermatol. 2021
Tested: coconut oil vs mineral oil across washes
Result: Coconut oil, not mineral oil, strengthened twisted fibres across washes.
Read the study ↗Loden M. Role of topical emollients and moisturizers in the treatment of dry skin barrier disorders. Am J Clin Dermatol. 2003
Result: Reviews how emollients and occlusives support the skin barrier; petrolatum-type films are strongly occlusive.
Read the study ↗Show 2 more studies
Plewig G, Fulton JE, Kligman AM. Pomade acne. Arch Dermatol. 1970
Result: Describes acne on the forehead and hairline linked to heavy, oily pomades (PubMed record has no abstract).
Read the study ↗Rubin IK. Efficacy of a Non-Comedogenic Hair Care Regimen for the Reduction of Mild-to-Moderate Truncal and Facial Acne: A Single-Arm 8-Week Study. J Drugs Dermatol. 2021
Tested: non-comedogenic hair-care regimen
Result: Truncal acne improved in 70% and facial acne in 52%. Single-arm and uncontrolled.
Read the study ↗Related
- LanolinA sheep-wool wax used as an emollient in pomades and conditioners; a weak but real contact allergen whose true allergy rate is probably under-detected.
- BeeswaxThe classic hold-and-grip wax in pomades and braiding waxes; harmless for most people but a documented contact allergen for a minority.
- Candelilla waxA plant wax from a Mexican desert shrub, used as the vegan alternative to beeswax in pomades and balms.
- Styling products explainedStyling products come down to how much hold and how much shine you want; there are almost no head-to-head trials, so this page combines formulation knowledge with the few things that have been measured.