They Say It’s the Same But It Isn’t the Same

When I was in the U. K. I ran out of toothpaste so I ran down to the chemist’s and picked up another tube. Same brand, same variety. When I got home I had occasion to compare the tubes of the stuff I bought here with the stuff I bought in the U. K. and was a bit surprised to note that they were different. Here’s the list of active ingredients on my U. S. toothpaste:

• Potassium nitrate
• Sodium fluoride

and here’s the list from the U. K. version:

• Arginin

My first reaction was to wonder if some of the ingredients in my U. S. toothpaste were banned by the EU. That didn’t explain it. I’ve come up with two different possible explanations, both of which might be true:

• Consumers in the U. K. are more sensitive about chemical-y sounding things than U. S. consumers are.
• The U. K. brand is the successor product to a product originally produced by a company that P&G acquired. The U. K. ingredients reflect the ingredients of that product and what its U. K. customers are accustomed to.

I’m open to other suggestions. Why is the same toothpaste different in two different countries?