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SkinSerums, creams, oils, gels, and balms
Product formats are physical structures, not tiers of quality.
By HELM Editorial · EditorialUpdated 8/9/2026
Key takeaways
- —Format describes physical structure, not strength or quality.
- —Serums are usually water-based and lightly thickened.
- —Creams are emulsions — oil and water held together by an emulsifier.
- —Oils and balms are anhydrous: no added water, so preservation needs differ.
Product formats are often presented as a hierarchy, with serums treated as the potent tier and creams as the basic one. Structurally, that is not what separates them. Format describes how a formula is physically built.
Solutions and serums
A serum is typically water-based, lightly thickened, and low in oil. Because there is little to no oil phase, it spreads thinly and absorbs quickly. That is a texture outcome, not a potency outcome.
Emulsions: lotions and creams
Lotions and creams are emulsions — oil dispersed in water, or water dispersed in oil, held together by an emulsifier. The ratio of the two phases and the thickening system determine whether the result pours, spreads, or holds a peak.
Gels
A gel is a liquid held in a polymer network. It has structure without much oil, which is why gels feel light and often cool on application.
Oils and balms
These are anhydrous — no added water. Without water, the microbial risk profile changes substantially, which changes how the product is preserved and packaged. Balms are usually oils plus waxes or butters to give them body.
Terms in this article
- Emulsion
- A stable mixture of two materials that do not normally mix — most commonly oil dispersed in water, or water dispersed in oil.
- Anhydrous
- Containing no added water. Balms, oils, and many sticks are anhydrous products.
- Serum
- A lightweight, usually thin product designed to deliver a concentrated set of ingredients with minimal occlusive base.
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