Pet supplements, what 2026 H1 looks like in the data

Pet supplements went from a sleepy subcategory to one of the most algorithmically interesting on Amazon in about 18 months. The 2026 H1 data, pulled across 60 brands and the long-tail private-label noise around them, looks healthy on the surface and has three structural cracks underneath.

Headline numbers

• Subcategory GMV up 14.2% YoY (US) through April
• Top-10 brand concentration: 28.4% (down from 33.1% in Q4 2025)
• Median TACoS across the top 50: 13.8% (up from 11.2%)
• Private label share up 410 bps in six months, the largest sustained shift we’ve ever seen in pet
• Subscribe & Save penetration up 9 points to 47% of category GMV

Crack 1: Rufus is rewriting pet queries differently than human-product queries

We’ve been tracking Rufus’s behavior across categories, and pet supplements stand out. Long-tail intent queries, “supplement for senior dog with mobility issues,” “joint support for cats with kidney disease,” “anxiety supplement for small breed under 20 pounds”, are now generating 9-12% of total impressions, vs. 2-3% in non-pet categories.

That’s a structural advantage for brands with deep, specific catalog content. It’s a structural disadvantage for brands whose A+ still reads like a 2022 SKU page (broad benefit claims, hero ingredient story, lifestyle photo of a happy dog). The detail page that wins in this market is the one that answers the specific intent, not the one that positions the brand. Most of the top-10 are still positioning.

Crack 2: Subscribe & Save is masking organic-share weakness

S&S penetration at 47% sounds like a good thing, recurring revenue, predictable demand, lower volatility. It is, mostly. But it also means a chunk of every brand’s GMV is locked into existing customers who aren’t price-shopping or query-shopping monthly. The new-customer acquisition layer of the category is thinner than the headline GMV suggests.

When we strip the S&S revenue from the top-50 and look only at non-subscribed unit volume, growth slows from 14.2% to 6.8%. The discovery layer of the category, where new buyers find new brands, is growing roughly half as fast as the locked-in subscriber base. For a brand that didn’t establish S&S share in 2023-2024, the on-ramp is steeper than the category-level number suggests. We’ve watched two brands in this space spend Q1 trying to grow non-subscribed volume and miss their plan by 30%+; they’re now buying subscriber base from competitors via promotional acquisition, which is expensive and rarely sticky.

Crack 3: Private label is doing the catalog work

Private-label gain in pet supplements isn’t being driven by price. The cheapest generic SKUs aren’t winning, the ones with deep, specific A+ content are. We pulled the top-50 private-label SKUs that gained share in 2026 H1 and reverse-engineered their detail pages: 38 of 50 had FAQ modules with breed-specific or condition-specific questions, 41 of 50 had substitution-matrix-style comparison tables, and 47 of 50 had updated their A+ within the last 90 days.

Compare that to the established top-15 brands losing share: 4 of 15 had FAQ modules at all. Average A+ age was 14 months. The private-label SKUs aren’t winning on supply chain or brand. They’re winning because they did the Cosmo-aware catalog work the incumbents skipped.

What this means for a pet-supplement brand right now

If you’re in this category and your A+ hasn’t been touched in the last 90 days, you’re already losing share, you may not see it in the top-line yet because S&S is masking it, but the new-customer acquisition layer is bleeding. Three things, in priority:

First, do an A+ rebuild against your top-5 long-tail queries. Pull them from your ST report’s high-conversion tail. The questions Rufus is rewriting toward are oddly specific (breed, age, condition); your detail page needs to answer them in plain prose, not in keyword density.

Second, audit S&S churn separately from new-customer acquisition. They’re different problems and they require different fixes. The brands that confuse them spend their Q2 budget fixing the wrong number.

Third, watch private label. The brands gaining share in 2026 are showing up with deeper catalogs, not cheaper prices. If your competitive frame is still “we’re the trusted brand vs. the no-name SKU,” you’re describing a 2022 market.

What we’re watching in H2

Two things. Whether the established top-10 close the catalog gap (by July, or never), and whether the S&S layer in the category starts contracting as more buyers cycle off auto-replenishment of brands they’re not actively choosing. The brands compounding through H2 are going to be the ones treating catalog as a product with the same operational rigor they treat their supply chain.

Subscribe to the Operator Brief, H2 pet supplement update lands in early August.