Category expansion has peaked. Winners are differentiating, not scaling.
Something shifted in the collagen category around mid-2025, and most brands operating in it haven’t adjusted yet. Search volume looks healthy. Listings still convert. Ads still run at acceptable ACoS. On a dashboard, everything looks normal. Then you zoom out to twelve-month trends and the picture gets honest — the category stopped growing.
This report walks through what we’re seeing across supplement brands in the collagen category on Amazon US, what’s driving the slowdown, and what the brands that are still growing are doing differently.
Search volume for “collagen” and its variations has been effectively flat year-over-year on Amazon US. That’s not a bad signal on its own — mature categories don’t need search growth to stay profitable. The problem is what happens below the search.
Conversion rates are down roughly 14% across the category compared to the same period last year. Unit economics are tightening as more brands compete for the same sessions. Review velocity on new launches has slowed — consumers aren’t exploring new brands in the space the way they were in 2022 and 2023.
Meanwhile, the premium tier — brands priced $45 and up, generally with additional functional claims (joint health, hair and nail, gut-specific collagen peptides) — is growing around 22% year-over-year. This isn’t a category-wide decline. It’s a bifurcation.
Three things are happening at once.
The category is mature. Everyone who was going to try collagen has tried collagen. First-time-buyer velocity has slowed because the first-time-buyer pool is smaller than it was.
Generic competition has won the low end. The $19–$29 zone is now dominated by brands that are effectively interchangeable — same hydrolyzed bovine peptides, same flavor options, same packaging conventions. Consumers in that price band default to whatever’s at the top of search results, which means PPC gets more expensive and margin gets thinner. The floor has hardened.
The premium tier is differentiating on something specific. Not “better collagen” in the abstract — specific functional angles. Type I and III for skin. Type II for joints. Marine collagen for consumers who reject bovine. Added ingredients that target a specific outcome. The brands growing in the premium tier aren’t winning because they’re premium — they’re winning because they’ve picked a fight the generic brands can’t have.
Three patterns worth noting.
First, they’ve stopped competing on PPC in the generic keyword space. “Collagen powder” is a money pit at this point for most brands. The growing brands are either dominating a sub-keyword set (“marine collagen,” “grass-fed collagen peptides for women”) or they’ve invested in brand-aware demand — customers searching for the specific brand name, not the category.
Second, they’ve tightened their SKU lineup rather than expanded it. The instinct in a plateauing category is to add flavors, sizes, and formats. The growing brands have done the opposite — they’ve consolidated to their best-performing SKUs and put their advertising and listing effort into making those fewer products rank and convert harder.
Third, they’ve invested in off-Amazon demand generation. Not all of it — this isn’t a DTC pivot — but enough that a meaningful percentage of their Amazon conversions are coming from branded search or external referral, not pure Amazon discovery. That’s the single biggest difference between the brands growing and the brands stalling.
If you’re a collagen brand on Amazon doing $1M–$15M annually, the honest question is which tier you’re in. If you’re in the $19–$29 generic zone, the trajectory isn’t good — the math gets worse every quarter as more brands pile into the same spot. Protecting margin means either moving up, narrowing down, or diversifying where your demand comes from.
If you’re in the premium tier, the growth is real but it’s conditional on your differentiation actually being differentiated. “Premium collagen” isn’t a position. “Premium collagen peptides with hyaluronic acid and biotin for women 35+” is a position. The brands winning right now have picked specific positions and committed to them.
Either way, the category has changed. The playbook that worked in 2022 — launch, rank, scale PPC, expand SKU lineup — doesn’t work the same way in 2026. And the agencies and operators who haven’t noticed are the ones whose numbers will keep sliding quietly for another six months before the trajectory becomes undeniable.
Market Analyses are published the first Tuesday of every month. The next report covers the probiotics category — where the data is telling a different story entirely.
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