Shopify payment gateway doesn't allow the distribution of specific types of produce. Some of our users have reported receiving an email about their store violating their terms and agreements (See screenshot below): 

What type of produce is prohibited?

According to Shopify's Payments Terms of Service, prohibited produce includes "Pharmaceuticals and other pseudo-pharmaceutical products that make health claims (e.g. retinol creams, lash growth serums, products containing hyaluronic acid, etc.) and medical devices."

Shopify employees have later replied to the complains their customers and replied with the following: 

"...That can cover a lot of things, from products that are being marketed as medical with no evidence, items that aren't able to be sold in certain states or provinces (ephedrine is a great example), or items that don't have an FDA certification."

To sum up, distributing products such as protein shakes, skin care products, vitamins, herbs, supplements and many other is considered Prohibited Business and results in users not being able to use Shopify payment gateway for selling such produce. 

What can be done?

As an solution, you may want to switch to the alternative payment processors such PayPal or Stripe.