Tamper evidence
Updated
Tamper evidence in supplements carries more weight than in most categories, because the product is ingested and because the customer cannot assess it by any other means.
What it is for here
Showing that nobody has opened the tub between you and the customer. In a category where the contents are a uniform powder that could be anything, that assurance is doing real work.
It also protects you: a returned and resold tub is a tub whose contents you can no longer vouch for, and a visible seal is what makes a return decision obvious.
What counts
An induction membrane bonded across the tub mouth. A shrink band over the lid. A breakaway ring on the closure. An outer carton sealed with tamper-evident tape.
A tight lid is not tamper evidence, and neither is a sticker that peels cleanly.
Induction does both jobs
This is the point specific to powders. An induction seal is tamper evidence and the moisture barrier a hygroscopic product needs.
So unlike most categories, where tamper evidence is a pure cost, here it coincides with the thing you should be buying anyway. A shrink band gives evidence and no barrier; induction gives both for the price of a sealing unit and compatible liners.
That makes the decision unusually easy, and it is why induction is close to universal on supplement tubs.
Deciding
Induction for anything sold as a daily-use tub, which is most of what you will make.
Expect wholesale and retail buyers to require tamper evidence by name on a vendor form, with no discretion from whoever receives the delivery.
And settle it before ordering tubs, because induction constrains the liner and the lid, and the rim has to be flat and clean enough to bond to.