Can you be allergic to Botox or Dysport?

I am allergic to the Thimerosal in Botox. Does Dysport also have this preservative or is it thimerosal free?

Ok – I’m a little concerned here because the legitimate Botox and Dysport don’t have Thimerosal in them. See the attached photos of the labels’ nonactive ingredients below. Now I’m worried that somehow you got bootleg Botox?? Hope not!! For those of you who haven’t heard of this, it is a fairly common formaldehyde releasing preservative, often found in eye care and skin care products. It can cause allergic reactions.








Here’s why allergic reactions to Botox or Dysport are so extremely rare:

  •  Botox, Dysport and related “toxins” are huge molecules. Consequently, they stay where they are injected with only a small amount of diffusion (moving away from the spot injected).
  •  Allergic reactions are usually caused by small molecules.
  •  These products are very carefully formulated by legitimate companies, and “pure” as in free of bacterial proteins. Products made by companies in some parts of the world are not to be trusted.

The one ingredient to pay attention to:

Dysport only and this is lactose, which is derived from milk and may contain milk protein. If you are truly allergic to milk, get your allergists’ approval before getting treatment. Or, use Botox instead.

The human albumin is something we all have in our bodies already and is made in the lab.

Hope this helps, Dr. I

Dr. Brandith Irwin, MD

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Hi, I’m Dr. Irwin. I believe that consumers deserve a medically trained and unbiased skin care advocate.

  • All our content is written and researched by myself.
  • My medical office in Seattle has treated thousands of patients for 15+ years.
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