The “Naked” Neurotoxin: What’s Actually in Your Wrinkle Treatment

Medically reviewed by Sarah Long, DNP, APRN, FNP-BC — Clinical Lead, medAge  •  Updated May 2026

Most people think of neurotoxin as a single thing — “Botox.” But there are several brands on the U.S. market, and they aren’t identical. The real differences aren’t in the active ingredient; they’re in what’s packaged alongside it. Here’s what’s actually in the vial.

None of this requires a science degree to follow, and knowing it helps you understand why we made the choice we did.

The active ingredient is the same idea across all brands

Every botulinum toxin type A product works using the same core molecule — a purified protein, about 150 kilodaltons in size, that temporarily quiets the signal between nerve and muscle so the muscle relaxes and the overlying wrinkle softens. That core is the part doing the work in every brand, from Botox to Dysport to Xeomin.

So if the working molecule is essentially the same, where do the brands actually differ? In the company each molecule keeps.

The “extras” — and where they come from

In nature, the botulinum molecule travels wrapped in a bundle of accessory proteins called complexing proteins. They exist to protect the toxin in the harsh environment of the digestive tract. That’s a genuinely useful function — if you were swallowing it. But you’re not. It’s being injected into muscle, where those complexing proteins serve no purpose at all.

In fact, once the product is reconstituted for injection, the great majority of those complexing proteins simply detach from the active core and drift off, contributing nothing to your result. Depending on the brand, a vial may also carry other leftovers of the manufacturing process — bacterial remnants, or in some products a lab-added peptide. None of it makes your treatment work better.

Why “extra” isn’t harmless

Here’s the part that matters. Those unnecessary proteins can act as a kind of flag to your immune system. The more foreign protein your body is exposed to over time, and the more often, the greater the chance it starts to recognize and react to it. For most people getting occasional cosmetic treatment, this is not a pressing concern — but for long-term or higher-dose users, a lighter protein load is a sensible thing to want. (We go deep on this in our companion article on why neurotoxin sometimes stops working.)

What makes Xeomin the “naked” toxin

Xeomin is manufactured differently. It goes through an additional purification — a double-filtration step the maker calls Xtract Technology — that removes the complexing proteins, leaving essentially just the active 150-kilodalton neurotoxin. It’s the only botulinum toxin approved in the U.S. that contains no complexing proteins and no virally-derived peptide additives, and it carries the lowest total protein load of the available toxins. That’s the reason it’s often described as the “naked” or “pure” toxin.

The two stabilizers left in the vial are human serum albumin — the most abundant protein in your own blood — and sucrose, a simple sugar. Both have long, well-understood safety records.

Does “purer” mean better results?

Not in the way people assume. In head-to-head studies, Xeomin’s effectiveness and how long it lasts are comparable to the other leading toxins — it is not stronger, and it won’t give you a dramatically different day-one result. Its advantage is subtractive: it’s about what’s left out, which is most relevant as a long-game strategy for people who plan to use neurotoxin for years. Because the products differ, units of one toxin can’t be directly swapped for another — dosing is always tailored by your injector.

Straight talk: Direct head-to-head studies proving that removing these proteins makes one brand less likely to cause resistance than another haven’t been done, so no manufacturer can claim outright superiority — and we won’t either. What we can say is that the composition is simpler, the purity is real and verifiable, and it’s the profile we prefer for our patients over the long run.

Why we chose it

We use Xeomin at medAge because, all else being comparable, we’d rather give you the working molecule and as little of the unnecessary extras as possible. It’s the same philosophy we bring to everything here — do the effective thing, skip what doesn’t earn its place.

Frequently asked questions

What’s the difference between Xeomin and Botox?

Both use the same active neurotoxin. The difference is purity: Xeomin is double-filtered to remove the complexing proteins that ride along in some other products, so it’s often called the “naked” toxin. Effectiveness and duration are comparable in head-to-head studies.

Is Xeomin as effective as Botox?

Yes. In head-to-head studies, Xeomin’s effectiveness and how long it lasts are comparable to the other leading neurotoxins. It isn’t stronger — its distinction is a simpler, purer composition, not a bigger result.

What’s actually in Xeomin?

Essentially the active 150-kilodalton neurotoxin plus two well-established stabilizers: human serum albumin (the most abundant protein in your blood) and sucrose. It contains no complexing proteins and no virally-derived peptide additives.