
Lot's of stores allow you to stack manufacturer coupons as long as one is a store coupon and one is a manufacturer coupon. Here is all the information you need to know to stack coupons at CVS
Can I use multiple coupons on sale items?
Yes, for certain coupons and certain sale items. Examples:
Suave shampoo is on sale for $2.00 Buy One, Get One Free (BOGO) and the customer purchases two shampoos; the customer may use two coupons for $1.00 each and pay the applicable tax.
Suave shampoo is on sale for $2.00 BOGO and customer has a mfr. coupon for Suave BOGO. Customer will receive both items for free but will need to pay any applicable tax.
All coupons are market appropriately. Manufacturers coupons will say Manufacturers.
CVS Store coupons may contain the following. STORE COUPON, CVS Coupon, Have the CVS Logo

Manufacturers Coupon;
Can be stacked with
CVS Store Coupon
CVS Store Threshold Coupon

CVS Store Coupon; Can be found at the CVS Savings Center (red Box) or in your CVS APP
Can Be Combined With
Manufacturer Coupon
CVS Threshold or Basket Coupon

This is a basket or threshold coupon. These are normally worded to be a blanket of products such as haircare, laundry etc.
Can be found at the CVS Savings Center (red Box) or in your CVS APP
Can Be Combined With
Manufacturer Coupons
Can be combined with other CVS coupons such as $2.00 off 2 Suave , states specific brand etc.
Here is an example of how you could use all the above three coupons at CVS
Deal; Suave Hair Care 2 for $6.00; Get $4.00 ECB when you spend $12.00; Limit 2
Buy 4=$12.00
Use 4 of the $0.75 off manufacturer paper coupons=-$3.00=$9.00
Use 1 $2.00 off 2 Suave Store Coupon=$7.00
Use 1 $3.00 off $12.00 Threshold Coupon=$4.00
Get back $4.00 ECB=
This will make your cash out of pocket $4.00 prompting a $4.00 ECB making your final price FREE