What Is Jojoba Oil, What Does It Do? Actually a Liquid Wax

Jojoba is a shrub growing in the arid regions of North America, and a liquid substance is extracted from its seed. On labels it appears as Simmondsia Chinensis (Jojoba) Seed Oil. It has "oil" in its name, but chemically it is not in the same family as olive oil or sunflower oil. Its structure is closer to sperm whale oil. This difference is what explains its behaviour on the skin and its resistance to spoilage.

Why is jojoba considered a liquid wax rather than an oil?

Most vegetable oils are triglycerides, that is, three fatty acids bound to a glycerol molecule. Jojoba has no glycerol: a long-chain fatty acid is bound to a long-chain alcohol, forming a wax ester.

Because of its melting point, it may solidify or turn cloudy in the fridge or a cold bath. If it returns to liquid at room temperature, that is not a sign of spoilage.

Is it the same as sebum?

The most repeated sentence is that "jojoba resembles the skin's own oil". This sentence is half true. Sebum is not a single substance but a mixture, and wax esters are only one part of it. The general picture, though proportions vary by measurement method, is as follows:

So jojoba resembles the wax ester part of sebum, which corresponds to about a quarter of it. The claim that it "tells the skin not to produce oil and balances sebum" is a different matter: we know of no human study measuring this. Similarity is not proof of effect.

Is it used on oily, acne-prone skin?

Two data points are often cited, and both have limits. In the first, refined, pure and hydrogenated jojoba samples were examined by hair follicle biopsy in 25 people, and no comedone formation was seen. Among the researchers of this study are people from a jojoba growers' association. In the second, a clay and jojoba mask was used 2-3 times a week for 6 weeks by people with mild acne. Among the 194 responders, the 133 people who counted correctly saw total lesions fall by an average of 54%. But there was no control group, participants did the counting, and the contribution of the clay cannot be separated.

These data do not show that jojoba works for acne; at most, they suggest it may be a reasonable oil choice for acne-prone skin. For regular care, the oily skin care article is a more solid starting point.

Why doesn't it spoil easily?

Most fatty acids have a single double bond, and tocopherols protect the oil itself. About 79% of these tocopherols are in the gamma form. In an accelerated heat test, jojoba's resistance to spoilage lasted longer than olive, sunflower and rosehip oils. The test was carried out at about 100 °C, so it cannot be transferred unchanged to room conditions, but the ranking is consistent with the structure. One warning: in refined or bleached oil the antioxidants decrease, so resistance also decreases. So keep the bottle closed and do not use oil that smells sour.

What else has been shown on skin and hair?

• Immune signals: In cultured living human skin tissue, jojoba wax reduced inflammatory signals (IL-6, IL-8, TNF-alpha) by about 30%, and increased production of the type III collagen precursor and hyaluronic acid. This is not a study in living humans.
• Barrier: Reviews rate jojoba positively as an emollient on dry skin with a weakened barrier, but the studies they rely on are small. Not enough to state firmly that it repairs the skin barrier.
• Hair: In a hair-straightening emulsion, jojoba wax acted as a conditioner and contributed to breakage resistance. The common use rests mainly on the general behaviour of oil: it makes the strand surface slippery. We do not have solid human data showing that it grows hair. If you have dandruff or itching on the scalp, first investigate the cause; the scalp care article provides guidance on this.
• Irritation: No marked sensitisation was seen in human patch tests; only one person showed a brief mild reaction. Rare does not mean never. Test on the inner arm or elbow crease twice a day for 7-10 days before applying to the face.