Hide Add charge product from 'Related Products' section

Sometimes, the add charge product will be visible on a section of your theme, the "You may also like" or related product section.

This section is mostly generated automatically by the Shopify algorithm to complement products with the same attributes. It is visible as a block on the Product page.

There are 2 main ways to hide the add charge product from this section,

Solution A. Replace this section with Featured Collections section

Navigate to the Customize theme section

Direct to any product pages, click + Add section, select Featured Collections

Select the Collection that doesn't include add charge product and hide the "Related Products"

Hit Save

Install Shopify Search & Discovery (FREE) app on Shopify App Store
Once installed, click on Recommendation section

Click add recommendation or click on any products on the table
Select Complementary Products (A block inside Product information section), or Related Products (A section on the product page)

Tick "Hide auto-generated recommendations"
Hit Save

The related/complementary products selected from this section is specially customized for each products and any products that doesn't have this selection will have auto-generated Related products section and it will have a high chance of showing the add charge products.