Spicule skincare: why these cosmetics sting and what happens to the skin

Spicules are microscopic, needle-like structures derived from the skeletons of certain marine sponges. When processed and incorporated into a cosmetic product, they create temporary microchannels in the stratum corneum: hence the tingling, and the nickname “microneedling in a bottle.”

The comparison helps explain the sensation, but it risks making people think that a cosmetic containing spicules is equivalent to a standardized professional procedure. It is not. And above all: if a product stings, that does not automatically mean it is more effective.

Cover image generated with the support of artificial intelligence.

[INDICE:h2]

Why they sting

During massage, the microstructures come into contact with the skin’s most superficial layer. This causes tingling, a needle-like sensation, and sensitivity to touch that, depending on the product, may continue even after application.

This perception makes the experience very convincing: feeling something seems to prove that the product is working. In reality, the sensation mainly confirms a mechanical interaction. On its own, it does not measure the clinical result.

It is the same misconception that makes a cream that feels warm seem to work better than one that does nothing: we are evaluating sensory feedback, not the outcome.

Spicules and microneedling are not the same thing

The nickname “microneedling in a bottle” is effective, but it brings together two things that are only superficially similar.

Professional microneedling uses devices with needles of predetermined length and depth, selected according to the objective and the area, with hygiene, disinfection, and single-use protocols. The operator knows exactly how deep they are going and for how long.

Spicules are massaged over the skin’s surface in a cream or serum. They are distributed unpredictably, with their orientation and the pressure depending on how the product is applied and by whom. Both techniques temporarily alter the barrier, but the degree of control is very different.

The practical consequence is this: with microneedling, the operator determines the variable; with spicules, you determine it without realizing it, and it changes with every application. This is not a reason to avoid them, but it is a reason not to consider them the at-home, cheaper version of an outpatient procedure.

Penetration of active ingredients

The skin barrier deliberately limits the entry of many substances: that is its job. Experimental studies show that spicules can increase the penetration of molecules that would otherwise have difficulty crossing the skin.

In 2025, a study on an antimicrobial peptide observed increased penetration when the peptide was combined with sponge spicules. These are interesting findings for delivery technology, but they do not demonstrate that every serum containing spicules makes every active ingredient effective.

This is the distinction I always make: a delivery system demonstrates something about that active-vehicle pair, not about the entire category. The same caution applies to high-molecular-weight active ingredients, which I wrote about in relation to PDRN.

Size changes everything

There is a 2019 study that, in my opinion, should be read by anyone who talks about spicules as though they were a single category.

The researchers prepared three versions of the same cream, changing only the size of the spicules: whole, broken, and powdered. The whole spicules, approximately 177 microns long, produced the highest permeation of a model protein, but they also caused irritation, pain, and redness. The broken spicules achieved slightly lower permeation, with no statistically significant difference, and considerably better tolerability. They were the ones selected for the human phase.

In other words: two products that both claim to contain “sponge spicules” can behave completely differently on the skin, and the difference lies not in the ingredient but in the processing, which the label does not explain. This is why judging the entire category as a whole, in either direction, makes little sense.

What the first cosmetic studies show

In 2025, a system with nano-encapsulated spicules was evaluated in a single-arm clinical study, examining parameters such as absorption, pores, texture, wrinkles, and pigmentation. The field is therefore moving from experimental models alone to evaluations in humans, and that is real progress.

Questions remain about the number and size of the spicules, distribution, dose, frequency, and comparison with formulas without the same technology. A single-arm study, meaning one without a control group, tells us much less than it may seem. And a result obtained with a specific system does not automatically apply to the entire category.

“Tingling must not become the new measure of effectiveness.”

Sensitive skin and combining with other active ingredients

Since the principle involves temporarily altering the barrier, greater caution is needed with sensitive skin, irritated skin, active dermatitis, or inflamed acne. Combining them with retinoids, acids, or other potentially irritating ingredients should also be considered carefully: if you increase penetration, you also increase the penetration of whatever causes irritation.

If persistent burning, swelling, or significant redness occurs, it is not a sign that the product is working. It is a sign that, on that skin, the product is doing too much.

In 2025, an editorial published in the Journal of the American Academy of Dermatology drew attention to the potential risks of silica spicules in cosmetics intended for home use. This is an important signal, and it should be understood for what it is: not a condemnation, but a reminder that innovation and safety assessment must advance together.

My perspective

I am genuinely interested in spicules because they address the most concrete limitation of topical cosmetics. But a technology that increases penetration creates opportunities while also increasing the need to know precisely what we are making penetrate, in what quantity, and into which skin.

I would always evaluate the complete formula, concentration, method of use, and tolerability. And I would be wary of any product that uses the sensation as its main selling point: when sensory experience becomes the proof, it often means that the real evidence is limited.