Brand Competition in U.S. Amazon Supplements: 2023 Insights

Executive Summary#

The U.S. Amazon dietary supplements market reached US$ 9.6 billion in 2023 — yet its top 10 brands collectively hold only ~10% market share. No dominant incumbent locks out challengers. Brands that target focused subcategories, invest in platform-native marketing, and move into high-growth formats such as gummies stand to gain disproportionate share in a fragmented, fast-growing channel.

A Rare Structural Opening: CR10 at ~10%#

Most mature e-commerce categories reach CR10 concentration ratios of 30–50%, where a handful of leaders capture the majority of sales and newcomers face steep barriers to visibility. The U.S. Amazon VMS (Vitamins, Minerals & Supplements) market is a meaningful exception.

Despite generating US$ 9.6 billion in 2023 sales at +15.5% YoY growth, the top 10 VMS brands on Amazon — including Garden of Life, Pure Encapsulations, and MaryRuth Organics — hold a combined CR10 of approximately 10%. No brand commands category-defining dominance. The leaders rank ahead of the field, but none controls the kind of share that makes displacement economics unfavorable for a well-resourced challenger.

This structural condition arises from the inherent diversity of the supplement consumer. Health goals, preferred dosage forms, lifestyle segments, and trust signals vary across immunity seekers, sports performers, senior wellness buyers, and beauty supplement users. This heterogeneity prevents any single brand from locking in the whole market, and it creates sustained space for specialists to lead in focused niches.

For brands evaluating U.S. Amazon as an expansion channel — particularly Chinese cross-border brands with established manufacturing and formulation capabilities — the fragmentation signal is actionable: targeted clinical positioning and platform-native execution can yield meaningful share gains without needing to displace entrenched incumbents.

Category Competition: Where the Volume Is and Where Growth Is#

Within the VMS umbrella, competitive intensity is unevenly distributed. Vitamins, minerals, and herbal supplements account for more than 60% of total U.S. Amazon VMS sales combined — the core battleground where established brands compete on price, format breadth, and subscription programme performance (Amazon's Subscribe & Save).

Digestive health is the standout subcategory for competitive strategy. It reached US$ 740 million in 2023, driven by growing consumer awareness of the gut-brain axis, post-pandemic interest in immune resilience, and mainstream clinical coverage of probiotics and prebiotics. The category remains meaningfully underpenetrated relative to the broader VMS market, creating runway for both established brands extending into digestive health and challenger brands positioning around science-backed gut formulations. Probiotic awareness has been amplified by social media health content, generating inbound consumer demand that well-positioned Amazon listings can capture organically.

The strategic implication for brand builders: the 60%+ share held by vitamins, minerals, and herbals represents volume, but digestive health represents the growth asymmetry — the subcategory where market position is still being established and where differentiated clinical claims can command price premiums.

Format Competition: Gummies Disrupt the Capsule Incumbent#

Competitive dynamics on U.S. Amazon are not only about subcategory choice — format is a primary dimension of differentiation that determines both addressable audience and growth trajectory.

Capsules retain 47% of total VMS format share, the largest single segment. Their incumbency is grounded in long-established efficacy profiles, manufacturing cost advantages, and consumer familiarity built over decades. Tablets and powders hold additional share, with powders particularly entrenched in sports nutrition.

Gummy supplements, however, posted US$ 660 million in 2023 sales growing at over +50% YoY — the highest growth rate among all dosage forms. A Harris Poll survey found that 28% of U.S. adults tried vitamin gummies in the past year; of those, 53% reported daily use. That conversion rate from trial to sustained habit is unusually high for a format innovation and signals genuine behavioural adoption rather than novelty-driven trial.

The mechanism driving gummy growth is consumer psychology: gummies remove the psychological association of supplement-taking with medication, widening the addressable audience beyond committed health consumers to casual wellness participants — a larger and faster-growing cohort. Brands with incumbent positions in capsule formats face a clear strategic decision: extend into gummies (and liquids, which are the next high-growth frontier) or accept gradual category share erosion as format preferences shift.

The competitive opening in gummies is still live. Because gummy formulation and manufacturing require different capabilities than traditional capsule production, many incumbents have been slow to transition. For brands with ready access to contract manufacturing infrastructure, this represents a timing opportunity.

Pricing and Platform Strategy#

The highly fragmented brand landscape on U.S. Amazon shapes pricing dynamics in a specific way: there is no dominant incumbent setting category price anchors. This means that price positioning is more negotiable than in concentrated categories, but it also means that premium positioning requires clear substantiation — clinical claims, third-party certifications (NSF, USP, Informed Sport), or influencer-driven trust signals — to justify the premium to consumers trained to compare across dozens of undifferentiated alternatives.

The Subscribe & Save mechanism is a critical competitive lever. Brands that convert initial purchasers into subscription subscribers build repeatable revenue streams with materially lower customer acquisition costs than single-purchase competitors. High subscription conversion correlates with:

• Strong verified review density (star rating 4.5+ across 1,000+ reviews)
• Consistent formulation and packaging (avoids churn from reformulation)
• Subscribe & Save pricing discounts (typically 5–15%)
• Fulfilled by Amazon (FBA) logistics for delivery reliability

Brands competing in the core vitamins and minerals segments — where price sensitivity is higher — need to compete on unit economics and SKU breadth. Brands entering digestive health or gummies with differentiated clinical claims can target higher ASPs and thinner subscription discount structures.

Key Takeaways#

• The CR10 concentration ratio of ~10% is atypical for a market of this size and signals persistent openness to challenger brands with focused positioning
• Vitamins, minerals, and herbal supplements hold 60%+ combined category share — high volume, high competition
• Digestive health reached US$ 740 million in 2023 and remains underpenetrated — the clearest subcategory growth opportunity
• Gummy supplements grew over +50% YoY to US$ 660 million; 53% of trialists converted to daily use — the format transition is structural, not cyclical
• Platform strategy (Subscribe & Save, review velocity, FBA fulfilment) is as important as formulation in determining brand competitive position on Amazon

About the Data#

This article draws on Moojing's January 2024 brief on the U.S. Amazon Dietary Supplements market. Quantitative data covers the full calendar year 2023 as tracked by MoAnalysis, Moojing's cross-border e-commerce intelligence platform. Consumer survey data on gummy adoption and usage frequency is sourced from Harris Poll. Market size forecasts for the global and U.S. dietary supplements market are from third-party analyst projections as cited in the source report.