Choosing a carrier oil for skin and hair

Carrier oils make up the largest part of most oil phases, which means they largely determine how a finished product feels on skin or hair. They are also the ingredient most often chosen on price alone. This article covers what actually distinguishes one from another and how to narrow the field for a specific brief.

What a carrier oil is doing in the formula

Three jobs, usually at once.

It dilutes. Essential oils and concentrated actives are not applied neat, and the carrier is what brings them to a usable strength and spreads them evenly across the skin.

It conditions in its own right. A carrier is not inert filler — it is an emollient, and in a simple product it may be the main thing doing the work.

It sets the sensory character. Whether a cream feels light or rich, whether a hair oil looks glossy or greasy, whether a serum absorbs or sits on the surface — the carrier decides most of that, and it is what a customer notices first and complains about first.

The distinctions that matter

Weight and absorption. Some oils sink in quickly and leave little behind; others sit on the surface and stay there. Neither is better. A face serum for oily skin and a body butter for dry skin want opposite ends of that scale, and the most common formulation error is choosing an oil for its reputation rather than its feel.

Oxidation stability. Oils go rancid, and they do it at very different rates. As a general rule of the category, the more unsaturated an oil, the faster it oxidises, and the more it benefits from an antioxidant in the formula and from being kept cool and dark. Rancidity shows up as an off smell first, long before anything else, and by then the batch is finished. In a warm climate this is not a theoretical concern.

Colour and odour. Some oils carry strong natural colour and scent into the finished product. That is a formulation constraint, not a fault — it just has to be planned for rather than discovered at the fill stage.

Cost against use level. An expensive oil used as a small part of the oil phase for a specific benefit can be cheaper in practice than a mid-priced one used as the bulk.

The oils Cerium lists

The current range is Aloe Vera Oil, Argan Oil, Avocado Oil, Black Seed Oil, Carrot Seed Oil, Olive Oil (Extra Virgin), Olive Oil Pomace, Papaya Seed Oil, Rose Petal Oil, Rosehip Oil and Turmeric Oil.

Two things are worth pointing out about that list.

The first is that it contains both Olive Oil (Extra Virgin) and Olive Oil Pomace. These are different materials at different price points, produced by different processes from the same fruit, and they are not interchangeable in a formula or on a label. If a formula was built on one, do not substitute the other without retesting.

The second is that several of these are bought for a specific reputation — argan for hair, rosehip for facial oils, black seed for its traditional use. That reputation is often what sells the finished product, so it belongs on the label. What does not belong is a performance claim you cannot support.

Working out which one you need

Start with the brief, not the ingredient list.

• For a facial product for oily or combination skin, look at the lighter, faster-absorbing end of the range.
• For a body butter or a rich balm, weight is the point rather than the problem, and richer oils are the ones you want.
• For a hair oil, shine and slip matter most, and the customer's tolerance for residue is the real constraint.
• For anything where the natural colour of the oil would carry through to the finished product, decide early whether that colour is a feature or a defect.

Then order samples and make trial batches. There is no substitute for feeling the finished product on skin, and no specification sheet will tell you whether your customer will like it.

Storage, which decides more than most people expect

Buy what you will use in a reasonable period rather than the largest drum available. Keep oils cool, dark and closed. Fill smaller working containers rather than repeatedly opening a large one, since each opening introduces air. If a product's shelf life is important to the brief, plan the antioxidant strategy at the formulation stage rather than adding one after a stability problem appears.

Confirm handling and storage conditions for the specific batch you buy against the documentation supplied with it.

Sourcing

Cerium supplies all eleven of the oils above from Nairobi, along with the butters, extracts and emulsifiers that go into the same formulations. If you are choosing between two oils for a specific product, the team can talk through the trade-off — send the brief through the enquiry form.