TB-500 in the Netherlands: legal status

In the Netherlands, TB-500 has no marketing authorisation. The College ter Beoordeling van Geneesmiddelen (CBG-MEB), the Dutch Medicines Evaluation Board, publishes the Geneesmiddeleninformatiebank, the official national register of all authorised human medicines^[1]. A search of that register returns no listing for thymosin beta-4, TB-500, RGN-259, or timbetasin, the WHO-assigned international non-proprietary name for full-length thymosin beta-4. The EMA medicines register similarly returns no marketing authorisation, EPAR, or referral for any of those names^[2]. That status has not changed in the past twelve months.

This page covers the legal framework that applies, the WADA sport-ban that has been in force since 2018, what the absence of marketing authorisation means for import and supply, and where the regulatory picture may move. For the full cross-country picture see TB-500 regulatory status by country. For the broader context of what TB-500 actually is and what the literature says, see the TB-500 overview page.

Table of contents

1. The Geneesmiddelenwet framework: what 'no marketing authorisation' means 2. The CBG-MEB and the national register 3. The 2018 WADA listing: TB-500 banned in sport 4. Import and supply: what the law permits and what it does not 5. What changed in the last twelve months 6. What we do not yet know 7. Medical and regulatory disclaimer

The Geneesmiddelenwet: what 'no marketing authorisation' means

The Geneesmiddelenwet (Medicines Act) is the Dutch legal framework governing the authorisation, manufacture, import, supply, and supervision of medicinal products. Under that law, a finished medicinal product may only be placed on the Dutch market if it has received a marketing authorisation from the CBG-MEB under a national procedure, or holds a central EU authorisation granted by the European Commission following a positive opinion from the EMA's Committee for Medicinal Products for Human Use^[2]. TB-500 and thymosin beta-4 have neither.

The functional definition of a medicinal product under Dutch law, which follows EU Directive 2001/83/EC, covers any substance intended for human use that is presented as having properties for treating or preventing disease, or that can restore, correct, or modify physiological functions through pharmacological, immunological, or metabolic action. TB-500 is marketed with claims about wound healing, soft-tissue repair, and tissue regeneration. If those claims are taken at face value, the substance meets the functional definition of a medicinal product under Dutch law, regardless of what any label on a vial says.

The practical consequence is that commercial sale of TB-500 vials as a product for human use in the Netherlands is not lawful. There are narrow exceptions for pharmacy-compounded preparations made for named patients and for clinical-trial materials authorised under the Clinical Trials Regulation. Neither exception applies to vials sold online to consumers under the 'research chemical' or 'peptide' label.

The CBG-MEB and the national register

The CBG-MEB is the competent authority for national marketing authorisations in the Netherlands. Its Geneesmiddeleninformatiebank, updated weekly, contains all medicines that hold a valid authorisation for the Dutch market^[1]. The database is searchable by product name, active substance, and ATC code. No record exists under thymosin, thymosin beta-4, timbetasin, TB-500, or RGN-259.

The CBG-MEB does not have a public enforcement list of named unauthorised products. Its enforcement function concentrates on entities seeking to place products on the Dutch market without authorisation. The Inspectie Gezondheidszorg en Jeugd (IGJ), the Dutch Health and Youth Care Inspectorate, carries out market surveillance and can take action against companies or individuals supplying unauthorised medicines. Personal import of small quantities for personal use occupies a grey zone in practice, but remains outside the scope of any exemption in the Geneesmiddelenwet.

The 2018 WADA listing: TB-500 banned in sport

For athletes subject to the World Anti-Doping Code, the status of TB-500 has been unambiguous since 1 January 2018. The United States Anti-Doping Agency's 2018 Prohibited List summary records that thymosin-beta4 and its derivatives, including TB-500 by name, were added as examples of prohibited growth factors under section S2.3 of the WADA Prohibited List^[3]. The substance is banned in competition and out of competition as a non-Specified Substance under the WADA Code.

Dutch athletes competing in WADA-compliant federations, which covers effectively all organised Olympic and professional sport in the Netherlands, are bound by the WADA Prohibited List through their federation's anti-doping rules and through the Dutch Anti-Doping Authority (NADO). For those athletes, using TB-500 is a doping violation regardless of how it was obtained or whether a prescribing doctor was involved. There is no Therapeutic Use Exemption pathway for TB-500 because no approved medical use exists in any jurisdiction we cover.

WADA's scientific-research programme has commissioned dedicated detection work on TB-500 metabolism in urine and plasma, which is the operational signal that anti-doping laboratories are actively testing for it^[4]. A Canadian athlete received a four-year ineligibility period for using BPC-157 and TB-500 together. The sanction picture is not hypothetical.

Import and supply: what the law permits and what it does not

The Geneesmiddelenwet restricts import of medicinal products that do not hold authorisation. Medicines subject to authorisation requirements may only be imported if they are authorised, or if they fall within a narrow set of statutory exemptions, such as named-patient supply through a licensed pharmacy for an individual who cannot be treated with an authorised equivalent. That exemption requires a qualified prescriber and a licensed pharmacy. It does not apply to online consumer orders.

In practice, Dutch customs enforcement against individual small-quantity parcels is inconsistent. Some parcels clear without issue; others are detained as unauthorised medicines. The inconsistency is enforcement variability, not legal permissibility. Packages marked 'research chemical' or 'for laboratory use only' do not receive different treatment under the law if the substance inside meets the functional definition of a medicinal product and the import is for human use.

Supply within the Netherlands faces the same framework. A person selling TB-500 vials to other consumers in the Netherlands is, in principle, supplying an unauthorised medicinal product. The Banned Substances Control Group notes that TB-500 is not FDA-approved and that unregulated manufacturing leads to inconsistent purity and potential contamination^[5]. Those quality risks apply equally to products reaching Dutch consumers through online vendors.

What changed in the last twelve months

No marketing authorisation has been granted or applied for in the Netherlands or at the EMA level for thymosin beta-4 or TB-500 in the period from July 2025 to July 2026. The CBG-MEB register reflects no change on this substance. RGN-259, the Tβ4 ophthalmic solution developed by RegeneRx and the ReGenTree joint venture, remains in clinical development; it has not received approval from the EMA or the CBG-MEB.

The development relevant to the wider regulatory picture is the FDA Pharmacy Compounding Advisory Committee meeting scheduled for 23 to 24 July 2026, at which TB-500 (free base and acetate forms) is among the peptides under review for the US 503A Bulks List. That committee advises on US compounding pharmacy rules; its recommendations do not bind the EMA or the CBG-MEB and will not change TB-500's status in the Netherlands. A 2026 review by Mayfield and colleagues in the American Journal of Sports Medicine noted that TB-500 and its parent peptide thymosin beta-4 showed angiogenic and tissue-repair activity in animal models but that human orthopaedic data are absent^[4]. The absence of that human evidence base is one reason no sponsor has filed for marketing authorisation in the EU.

What we do not yet know

Several questions relevant to the Dutch picture remain open. Whether the FDA PCAC's July 2026 review and any resulting US compounding rule change will accelerate or discourage EU-level clinical development is not yet clear. Whether RegeneRx will seek EMA approval for RGN-259, the ophthalmic formulation with Phase 3 data in neurotrophic keratopathy, is not public information as of this writing. If an EMA application were filed and approved, it would create the first EU-wide authorisation for a thymosin beta-4 product, though the ophthalmic indication would not cover the systemic injection use that drives grey-market demand.

The long-term safety profile of systemic TB-500 in humans remains uncharacterised. Preclinical work flags a theoretical tumorigenesis signal in some cancer-cell models. No completed randomised controlled trial of systemic thymosin beta-4 or TB-500 for tendon, ligament, muscle, or general tissue-repair indications has been published. Human safety data for the injection route consists of self-reports and small case series. What Dutch law says about the substance and what the science says about it currently point in the same direction: both leave the risk picture substantially open.

Medical and regulatory disclaimer

This article is for educational and journalistic purposes only and does not constitute medical advice. TB-500 is not an approved medicine in the Netherlands or anywhere else we cover. Under the Geneesmiddelenwet, it may be classified as an unauthorised medicinal product, and its sale for human use is not lawful. Always consult a qualified healthcare professional before considering any peptide product. PeptideMethods.com does not sell, distribute, or facilitate the sale of any peptide product.

Regulatory disclaimer: This page reflects our understanding of the regulatory status as of July 2026. Regulations change. Verify with the CBG-MEB or qualified legal counsel before making any decision based on this page. PeptideMethods.com is not a law firm and does not provide legal advice.