Last updated: July 2024

Peptides are used across skincare, sports nutrition, and biotech research — but selling them in the UK comes with payment and compliance challenges. Here's what merchants need to know, including how Pay by Bank via Fena supports compliant peptide payment processing on Shopify.

Peptides are everywhere — and so are the questions around selling them

Peptides sit at the intersection of several fast-growing markets: anti-ageing skincare, sports nutrition, and biotech research. They appear in serums, supplements, and scientific studies, and consumer interest in all three categories continues to grow in the UK.

For brands and merchants in this space, that growth comes with a specific set of challenges. Payment processors frequently classify peptide products as high-risk, even when they're entirely legal and properly labelled. Compliance with MHRA requirements adds another layer of complexity. And selling on platforms like Shopify requires navigating policies that weren't always written with specialist health and wellness products in mind.

This guide covers what peptides are, where they're used across beauty, fitness, and research, and what UK sellers need to understand about payment processing and compliance — including how Pay by Bank via Fena provides a workable path forward for Shopify merchants in this category.

Quick summary

• Peptides are short chains of amino acids, typically 2–50, that act as biological messengers influencing processes like collagen production, tissue repair, and hormone regulation

• In skincare, peptides support collagen synthesis, strengthen the skin barrier, and deliver visible anti-ageing results with consistent use

• In fitness and sports nutrition, peptides support muscle recovery, connective tissue health, and natural growth hormone regulation — differing mechanistically from anabolic steroids

• Emerging research is accelerating peptide development through AI-driven modelling, automated synthesis, and nanocarrier delivery systems

• UK sellers face real payment processing challenges in this category, with many gateways treating peptides as restricted even for compliant merchants

• Pay by Bank via Fena provides a transparent, FCA-regulated payment route for peptide sellers on Shopify UK, with built-in compliance tooling

What peptides are and why they matter

Peptides are essentially small proteins. Where a full protein might contain hundreds of amino acids, peptides typically contain between two and fifty — which makes them easier for the body to absorb and more targeted in how they act.

Their role as biological messengers is what makes them valuable across such different applications. Depending on their sequence and structure, peptides can signal skin cells to produce more collagen, stimulate natural growth hormone release, support cellular repair, or act as delivery vehicles for other compounds. This versatility is why the same class of molecule appears in a luxury face serum, a post-workout supplement, and a pharmaceutical research programme.

Peptides in skincare: what the science says

Skincare is where most UK consumers first encounter peptides, and the category has grown significantly as evidence for their effectiveness has accumulated. Collagen peptides for skin, signal peptides, and carrier peptides each work through distinct mechanisms, but all share the same basic purpose: supporting the skin's structural integrity and natural repair processes.

Signal peptides

— including well-known examples like Matrixyl and Argireline — communicate with skin cells to stimulate collagen and elastin production. Collagen provides structural strength; elastin provides the flexibility that allows skin to spring back. Both decline with age, and signal peptides are one of the more evidence-backed topical approaches to slowing that process.

Carrier peptides

work differently. Rather than signalling cellular behaviour, they transport trace minerals — copper is a common example, as in GHK-Cu — that support wound healing, skin repair, and regeneration. These are particularly valued in formulations aimed at compromised or mature skin.

Enzyme-inhibitor peptides

address the degradation side of the equation, blocking the enzymes that break down existing collagen rather than simply stimulating new production. Used alongside signal peptides, they preserve the structural proteins that give skin firmness and hydration.

The research on peptide skincare is substantive enough that evidence-based marketing isn't difficult — but transparent labelling and accurate claims remain essential, both for regulatory compliance and for building the kind of customer trust that drives repeat purchase.

Peptides in fitness and sports nutrition

In sports and fitness, peptides are used primarily for their role in supporting the body's natural recovery and growth mechanisms. The distinction between peptides and anabolic steroids is important — and worth understanding clearly, both for scientific accuracy and for how products are marketed and regulated.

Anabolic steroids work by introducing synthetic hormones or hormone analogues that directly replace or override natural regulation. Peptides, by contrast, typically act by stimulating the body's existing systems — prompting natural growth hormone release, supporting IGF-1 activity, or maintaining connective tissue health. The result is a different risk profile and a different regulatory context.

Growth hormone-releasing peptides (GHRPs)

are among the most studied in sports contexts. They trigger the pituitary gland to release growth hormone through natural pathways rather than supplying it exogenously. This supports muscle recovery, fat metabolism, and tissue repair.

IGF-1 peptides

support anabolic cellular activity and repair, particularly relevant during intensive training periods where recovery demand is high.

Collagen peptides

, well known in the skincare context, have a parallel role in sports nutrition — maintaining the integrity of joints, tendons, and connective tissue that bear significant load during training.

For sellers in this space, the regulatory environment is clear: products must comply with MHRA guidelines, labelling must accurately represent what the product contains and does not claim medical effects without appropriate authorisation. These requirements are non-negotiable, and payment providers increasingly look for evidence of compliance before extending processing services to merchants in this category.

Where peptide research is heading

The scientific development of peptides has accelerated considerably in recent years, driven by advances in three areas in particular.

Automated peptide synthesis systems have improved precision and purity to a level that makes custom peptide production viable at scales and costs that were impractical a decade ago. This has opened up research possibilities and enabled more sophisticated formulation work in both skincare and biotech.

AI-driven peptide modelling allows researchers to predict how a peptide sequence will behave structurally and biologically before it's synthesised in the lab. This dramatically shortens development cycles and enables more targeted design of peptides for specific applications — from skin barrier support to drug delivery.

Nanocarrier delivery systems address one of the persistent challenges in peptide application: stability and absorption. Peptides can degrade before reaching their target. Nanocarrier technology encapsulates peptides in protective structures that improve their stability in formulation, enhance skin penetration in topical products, and support targeted delivery in pharmaceutical applications.

For merchants selling in this category, staying close to the science is useful — not just for product development, but for the evidence-based communication that increasingly separates credible brands from those making unsupported claims.

The payment processing challenge for UK peptide sellers

Here is where the commercial reality bites. Peptides are legal, widely used, and increasingly well-supported by science. But many payment processors treat them as high-risk by default, which creates real operational problems for legitimate UK merchants.

The reasons are partly historical — peptides share regulatory space with other compounds that have more complex legal status — and partly systemic, in that automated risk classification systems often can't distinguish between a properly labelled collagen supplement and a research compound with restricted sale status.

The practical consequences for Shopify merchants in this category include payment gateways declining to process transactions, accounts being suspended without detailed explanation, and difficulty establishing stable processing relationships with providers who understand the specific compliance context.

This creates a real problem for compliant merchants who have done the work — appropriate labelling, MHRA awareness, age and identity verification where required — but can't find a payment provider that recognises it.

How Pay by Bank via Fena addresses this

Fena provides Pay by Bank as a payment method for UK Shopify merchants, and it is specifically designed to work in regulated and specialist product categories where standard card processing creates friction.

FCA-authorised infrastructure.

Pay by Bank via Fena operates under FCA regulation, using UK open banking payment rails rather than card network infrastructure. This is relevant for peptide sellers because it provides a regulated, transparent payment pathway that doesn't rely on the card network risk classification systems that typically flag peptide products.

Compliance tooling built in.

Fena's integration includes KYC (Know Your Customer) verification, age verification, and fraud prevention capabilities — the tools that compliant peptide merchants need to demonstrate responsible selling. These aren't add-ons to configure separately; they're part of the payment flow.

Full audit trails.

Every transaction is logged with the detail needed for compliance reporting and financial reconciliation. For merchants operating in regulated categories, this visibility matters — both for internal management and for demonstrating compliance if it's ever reviewed.

No chargebacks.

Because Pay by Bank transactions don't go through card networks, they aren't subject to card chargeback mechanisms. For merchants in categories that attract elevated dispute rates, this removes a significant operational and financial risk.

Shopify integration.

Fena connects to Shopify directly, adding Pay by Bank as a checkout option without replacing existing payment methods. Customers who prefer to use their bank account can do so; those who prefer cards still have that option available.

What this means practically for peptide sellers on Shopify UK

Running a compliant peptide business in the UK requires getting several things right simultaneously: product labelling, regulatory awareness, responsible marketing, age verification where applicable, and a payment stack that doesn't create friction for customers or risk for the business.

Pay by Bank via Fena handles the payment and compliance piece. It doesn't remove the obligation to sell responsibly — that remains with the merchant — but it provides a processing environment that recognises the difference between a well-run specialist retailer and the risk scenarios payment processors are actually trying to avoid.

For merchants who have built their operation on proper foundations and are frustrated by payment infrastructure that treats them the same as non-compliant sellers, Fena's approach is worth understanding in detail.

Frequently asked questions

What are peptides used for?

Peptides are used across skincare, sports nutrition, and biotech research. In skincare, they stimulate collagen production, strengthen the skin barrier, and support cellular repair. In fitness, they support muscle recovery, connective tissue health, and natural growth hormone regulation. In research and pharmaceutical development, they are used for targeted biological activity and drug delivery.

Do peptides actually work in skincare?

Yes, with caveats. The evidence for peptide skincare is substantive — particularly for signal peptides that stimulate collagen synthesis and carrier peptides that support repair. Results depend on the specific peptide used, its concentration in the formulation, and the stability of the product. Not all products marketed as containing peptides use them at effective concentrations.

How are peptides different from steroids for muscle growth?

Peptides typically work by stimulating the body's existing hormone regulation — prompting natural growth hormone release or supporting recovery processes — rather than introducing synthetic hormones. Anabolic steroids replace or override natural hormone systems directly. This mechanistic difference generally results in a different risk profile and a different regulatory context for peptides.

Can I sell peptide products on Shopify UK?

Yes, within the relevant regulatory framework. Products must be accurately labelled, claims must comply with MHRA guidance, and age verification may be required depending on the specific product category. The payment challenge is separate — many standard processors restrict peptide merchants even when the products and business practices are fully compliant.

Why do payment processors restrict peptide sellers?

Automated risk classification systems used by card-based payment processors often apply broad restrictions to health and wellness categories that include some regulated or restricted products. Compliant peptide merchants frequently get caught by these restrictions even when their specific products are entirely legal and properly labelled.

How does Pay by Bank via Fena help peptide merchants?

Fena provides a Pay by Bank integration for Shopify that operates under FCA authorisation and includes built-in KYC, age verification, and fraud prevention. Because it uses open banking payment rails rather than card networks, it isn't subject to the card processor risk classifications that restrict many peptide sellers. It provides a compliant, transparent payment route for merchants who have done the regulatory work.

Does using Pay by Bank affect the customer checkout experience?

No significantly. Customers choosing Pay by Bank authenticate the payment through their banking app — a flow that's familiar to the growing proportion of UK shoppers who use open banking services regularly. It appears as an additional payment option at checkout alongside any existing methods, not as a replacement for them.