The Packaging Choices That Protect (or Wreck) Your Supplement

Not under federal rules. The federal tamper-evident packaging rule (21 CFR 211.132) is written for over-the-counter human drug products, not for dietary supplements. But Amazon and most retailers require tamper-evident sealing, and a missing or broken seal reads as tampering to shoppers, so an induction seal or shrink band is standard practice at a few cents per unit.

When the product contains enough iron, at a high enough concentration. Under the Poison Prevention Packaging Act (16 CFR 1700.14(a)(13)), a dietary supplement holding 250 mg or more of elemental iron in a single package needs child-resistant packaging when it also meets that subsection's concentration thresholds and falls outside its exemptions. The milligram figure brings you into scope rather than settling it, and compliance attaches to the tested cap-and-bottle system. A narrow accommodation in 16 CFR 1700.5 also allows one non-complying size when complying popular-size packages are supplied too and that package carries the prescribed warning, so run the full test rather than stopping at the number. In April 2026, CPSC announced a recall of about 356,140 units across 11 brands for failing this. Some other concentrated actives also trigger it, so confirm your specific formula with your manufacturer.

HDPE blocks moisture roughly four times better than clear PET (moisture vapor transmission rate near 0.5 versus about 2.0), which is why HDPE is the common choice for moisture-sensitive powders, probiotics, and effervescents. PET is clearer and fine for products that are not moisture-sensitive. For oxidation-sensitive products like fish oil, amber glass is used because it blocks more light and oxygen.