Mineral Oil
A highly refined, clear oil from petroleum. It sits on the hair surface as a protective, water-resistant coating and does not penetrate the strand.
Curly Girl note: Not water-soluble and doesn't penetrate hair, so it can build up — the original Curly Girl Method avoids it.
About Mineral Oil
Mineral oil is a mixture of hydrocarbons refined from petroleum. Cosmetic grades are purified far beyond industrial oils, leaving a clear, odorless, very stable liquid that does not go rancid and rarely causes allergies. It has been a core ingredient in Black hair care for generations — in hair lotions, glossers, 'grease' and many relaxer kits.
On hair, mineral oil works purely on the surface. Studies comparing oils found that it does not enter the hair shaft and, unlike coconut oil, did not reduce protein loss during washing. What it does well is form a water-resistant coating: it adds shine, reduces friction, slows down water loss from the hair after moisturizing and gives a smooth, slick finish.
The drawback is build-up. Mineral oil is not water-soluble, so co-washing won't remove it; a cleansing shampoo will. Layer upon layer can make hair feel coated and limp and can stop water-based moisturizers from reaching the hair, which is why the Curly Girl Method avoids it. People with low porosity hair are usually the first to notice.
Who may still like it: people with relaxed hair, silk presses and very high porosity ends that lose moisture quickly, as long as they clarify regularly. Scalp-wise, cosmetic-grade mineral oil is considered safe and non-irritating; concerns about cancer relate to poorly refined industrial oils, not the purified grades used in cosmetics.
How our checker rates it
| Mode | Rating | Why |
|---|---|---|
| Curly Girl | Avoid | Mineral oil or petrolatum — seals but needs sulfates to remove. Not CG-friendly. |
| Relaxed hair | OK | No concerns for this mode. |
| Low porosity | Caution | Heavy ingredient near the top of the list — can sit on low-porosity hair and build up. |
| Protein-sensitive | OK | No concerns for this mode. |
Ratings assume it is listed near the top of the label. After the first preservative or fragrance (likely 1% or less) most cautions soften.
What mineral oil / petrolatum ingredients do
Petroleum-derived oils and jellies that seal very well but do not rinse off with gentle cleansers and can build up.
This one is on the heavy side, so it can weigh down fine or low-porosity hair if it sits near the top of a product’s list.
Also listed as
- paraffinum liquidum
- liquid paraffin
- white mineral oil
- paraffin oil
- paraffinum liquidum (mineral oil)
Similar ingredients
Sources
Last data update:
- Rele AS, Mohile RB. Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage. J Cosmet Sci. 2003;54(2):175-192. Coconut oil reduced protein loss in hair; mineral and sunflower oil did not.
- Keis K, Persaud D, Kamath YK, Rele AS. Investigation of penetration abilities of various oils into human hair fibers. J Cosmet Sci. 2005;56(5):283-295. Coconut oil penetrates the hair shaft; mineral oil does not.
- Robbins CR. Chemical and Physical Behavior of Human Hair. 5th ed. Springer; 2012. Reference text on hair structure, surfactants, conditioning agents, protein, heat and chemical treatments.
- Massey L, Chiu M. Curly Girl: The Handbook. Workman Publishing; 2011. Origin of the Curly Girl Method rules (no sulfates, no non-soluble silicones, no drying alcohols).
- Cosmetic Ingredient Review (CIR). Ingredient safety assessments. Safety assessments for cosmetic ingredients cited on ingredient pages.
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