Have you ever wondered what exactly you’re tasting when you lick a stamp or envelope? Is it safe? Is there any science behind it? Surprisingly, yes. Let’s dive into the sticky details.
What’s Stamp Adhesive Made Of?
Most stamps use a glue made from plant-based materials like dextrin (from corn or potatoes) or gum arabic. These ingredients are considered non-toxic and safe for indirect contact with your mouth.
Modern stamps may also use synthetic glues like polyvinyl alcohol, which are FDA-approved. So technically, yes, you can lick them. But would you want to?
Are There Calories in Stamp Glue?
It might sound strange, but yes, licking a stamp can give you a tiny calorie boost. A U.S. stamp has around 0.1 calorie. In the UK, some larger stamps may contain up to 14.5 calories due to more adhesive.
It’s hardly a diet-breaker, but still a fun (and slightly gross) fact.
Is It Safe to Lick Envelopes and Stamps?
Here’s where things get icky. Research shows that bacteria can survive on moist adhesive surfaces. Licking envelopes or stamps introduces moisture, creating a perfect environment for germs.
Plus, paper cuts on your tongue or lips—yes, it happens—can be painful and risky.
Are Stamp Glues Gluten-Free?
This is a common myth. People with celiac disease often worry about adhesives. But most stamp glues are made from corn or potato starch, not wheat.
The Envelope Manufacturers Association confirms most adhesives are gluten-free. Still, if you’re unsure, avoid licking and use a sponge or peel-and-stick stamps.
What About the Cockroach Egg Myth?
You may have heard a disturbing urban legend: someone licked an envelope and cockroach eggs hatched in their mouth. Total myth.
There’s no scientific evidence that envelope glue can harbor or hatch insect eggs. It’s just a creepy story that went viral decades ago.
Why Do We Still Lick Stamps Today?
Despite self-adhesive stamps being common, many older stamps and mass-mailing envelopes still use lickable glue. It’s cheaper, and machines can moisten them automatically during processing.
Some people also enjoy the nostalgic “personal touch” of licking a stamp—even if it’s a little weird.
A Bit of History
Back in the 1800s, people were already worried about licking glue. Devices like the “Mouilleur syphoïde” were invented to moisten stamps without using your tongue. Basically, a water wand.
Even then, the idea of putting glue in your mouth didn’t sit well with everyone.
Should You Stop Licking Stamps?
If you can avoid it—yes. It’s safer and more hygienic to use a sponge, roller, or self-adhesive stamps.
But if you do lick one occasionally, don’t panic. It’s not dangerous, just not ideal.
Final Thoughts
Licking stamps and envelopes may seem harmless, but there’s more going on than meets the eye. From minor calories to bacteria and myths, it’s a weird little window into science and history.
So, the next time you’re sending a letter—maybe leave the licking to the old days.