KLOW — identity, handling and published literature

KLOW is a laboratory blend designation for a single lyophilised preparation containing four separately named research peptides — BPC-157, TB-500, GHK-Cu and KPV — supplied together in one vial for research use only.

Presentation and physical properties

Supplied as a lyophilised solid in a sealed glass vial under vacuum or inert headspace. The labelled mass is the combined mass of all four peptides, not the mass of any one of them.

“KLOW” is a blend designation, not a chemical name. It has no International Nonproprietary Name, no CAS registry number, no PubChem CID and no monograph in any pharmacopoeia, because it is a mixture rather than a substance. There is no published standard defining the ratio of its four components. Two vials labelled KLOW from different sources need not contain the same proportions, and the proportions cannot be inferred from the total mass on the label. Each component has its own identity, and those identities are set out below and in the identification data accompanying this entry.

Three of the four components are white to off-white solids. GHK-Cu is not: the copper(II) coordination complex is blue to blue-violet, arising from d–d electronic transitions of the bound metal centre. A blend containing GHK-Cu will therefore carry a blue or violet tint in proportion to its GHK-Cu content, both as a solid and in solution. A KLOW preparation that is entirely colourless warrants investigation of whether the copper complex is present at the stated proportion.

A note on nomenclature that bears directly on reading the literature: TB-500 and thymosin β4 are not the same molecule. Thymosin β4 is a 43-residue protein. TB-500, as defined by the CAS number and formula above, is a synthetic seven-residue N-acetylated fragment corresponding to the actin-binding region. Material sold under the name “TB-500” may be either. The distinction matters when the published record is examined, because the two have very different evidence bases.

Reconstitution arithmetic

Reconstitution is a dilution calculation and nothing more. Total peptide mass in the vial divided by the volume of diluent added gives the concentration of the resulting solution:

concentration (mg/mL) = total peptide mass (mg) ÷ diluent volume (mL)

For an 80 mg total-mass vial:

Every figure in that table is the combined mass of all four peptides. It is not the mass of BPC-157, of TB-500, of GHK-Cu or of KPV. To obtain the concentration of any single component, the total concentration must be multiplied by that component’s mass fraction of the blend — and that fraction is a property of the specific preparation, declared by whoever made it. It cannot be derived from the total, and it cannot be assumed to be an equal quarter.

This is the practical consequence of blending: a single-component vial permits an exact per-component concentration to be calculated from the label, and a four-component vial does not. The arithmetic above is complete and correct for total peptide mass, and silent on composition.

Storage and stability

Lyophilised peptide is the stable form. Standard laboratory practice for research peptides of this type is storage of the sealed lyophilate at −20 °C or below, protected from light and from moisture ingress, with the vial allowed to reach ambient temperature before opening so that atmospheric water does not condense onto cold solid.

Once reconstituted, all four components are in aqueous solution and subject to hydrolytic and oxidative degradation. Refrigerated storage at 2–8 °C, protection from light, and avoidance of repeated freeze–thaw cycling are the conventional handling measures. Bacteriostatic water contains benzyl alcohol as a preservative and is used where a solution is to be held; sterile water contains no preservative and offers no protection against microbial growth after first entry.

Three stability considerations are specific to this blend rather than to peptides generally:

• Copper(II) is a redox-active metal centre. The GHK-Cu component introduces a transition metal into a solution that also contains three other peptides. Copper(II) is a well-established catalyst of oxidative degradation in peptide and protein formulations. None of the four sequences contains cysteine or methionine, which removes the most familiar thiol and thioether oxidation pathways, but the general catalytic concern is not removed with them.
• The copper complex is pH-dependent. GHK-Cu is a coordination complex, not a covalent molecule, and the histidine imidazole that anchors the metal is a titratable group. The complex is reported stable in aqueous systems in the region of pH 5 to 7 in the cosmetic formulation literature; outside that region the equilibrium between complexed and free copper shifts. Loss of the blue-violet colour is the visible indication of a complex that has dissociated.
• BPC-157 carries adjacent aspartate residues. The C-terminal region of the sequence (…Ala-Asp-Asp-Ala-Gly-Leu-Val) contains an Asp-Asp motif. Aspartate residues in peptides are subject to isomerisation and aspartimide formation in aqueous solution, which produces species of identical mass to the parent and is therefore invisible to a mass measurement alone.

No published stability study of these four peptides co-formulated in a single vial has been identified. Shelf-life and degradation behaviour of the blend as a blend is not established in the literature.

Analytical identity

Characterising a four-component blend is a materially different analytical problem from characterising a single peptide, and the usual single-substance methods do not transfer.

Reversed-phase HPLC with ultraviolet detection separates the four components, which differ widely in hydrophobicity and in chain length, and gives relative peak areas. Because the components have different molar absorptivities at the wavelengths conventionally used, peak area ratios are not composition ratios without calibration against reference standards for each component.

Electrospray mass spectrometry, coupled to the chromatographic separation, confirms the identity of each resolved species against its expected mass — nominally 1419.5, 889.0 and 342.43 for BPC-157, TB-500 and KPV respectively, with the GHK-Cu complex additionally identifiable by the characteristic isotope pattern of copper, whose two stable isotopes (⁶³Cu and ⁶⁵Cu, roughly 69% and 31% natural abundance) produce a distinctive doublet signature that free peptides do not.

Elemental analysis for copper, by inductively coupled plasma mass spectrometry or atomic absorption spectroscopy, quantifies the metal independently of the peptide and is the direct route to establishing GHK-Cu content.

Two analytical points follow, and both are consequences of blending rather than of any individual component:

• A single mass spectrum showing one expected peptide mass establishes the presence of one component. It says nothing about the other three, and nothing about proportions.
• A purity figure expressed as a single percentage is not defined for a mixture without first stating what the analyte is. “Purity” of a blend can only sensibly mean the proportion of total material accounted for by the four intended species, and that is a different measurement from the purity of any one of them.

What the published literature investigated

No controlled trial of this four-component combination as a combination has been published. A PubMed search combining BPC-157, GHK-Cu and KPV returns no records. No study registered on ClinicalTrials.gov investigates the four together; the register carries three entries mentioning BPC-157 at all, none of them of a four-peptide blend. The literature indexed below is therefore literature on the individual components, investigated separately, and it is set out that way deliberately. Findings from a study of one component are findings about that component under the conditions of that study.

Studies of two components administered together

One published study has examined any two of these components in combination. Biçer and colleagues reported in 2026 a four-arm experiment in male Sprague-Dawley rats following Achilles tendon transection, comparing control, BPC-157 alone, TB-500 alone, and BPC-157 with TB-500 together, assessed biomechanically and histopathologically [3]. The authors reported that TB-500 was associated with improved biomechanical measures and reduced pathological scores, and reported that the combination arm did not confer additional benefit over either agent given alone [3]. This is a rodent study of two of the four components; it does not address GHK-Cu or KPV, and it is the only published experiment located in which any of these peptides were co-administered.

Human trials

The human evidence is concentrated almost entirely on thymosin β4, and the distinction drawn in the identity section above governs how it should be read. The trials below investigated full-length recombinant or synthetic thymosin β4, a 43-residue protein — not TB-500, the seven-residue fragment.

A first-in-human randomised, double-blind, single- and multiple-dose phase I study of recombinant human thymosin β4 in healthy Chinese volunteers was published in 2021 [9]. An earlier randomised, placebo-controlled single and multiple dose study of intravenous thymosin β4 in healthy volunteers was reported in 2010 [11]. Sosne and colleagues reported a phase 2 randomised trial in severe dry eye in 2015, published in Cornea [10]. Guarnera and colleagues reported a European prospective randomised study of thymosin β4 in venous ulcers in 2007 [13] and further venous ulcer trial data in 2010 [12]. Goldstein and colleagues reviewed the basic properties and clinical applications of the molecule in 2012 [14].

That body of work is a genuine controlled human trial base, and it is fair to describe it as such. It is a trial base belonging to thymosin β4.

For BPC-157, no randomised controlled trial has been published. The reviews that cover the compound describe phase II work in inflammatory bowel disease conducted in Croatia under the development codes PL-10, PLD-116 and PL14736, and the rodent papers from that programme refer to those trials in their titles [7]; results of the human trials themselves have not appeared in the peer-reviewed literature. The one indexed human report located is an uncontrolled case series of intra-articular BPC 157 in knee pain, published in 2021 in Alternative Therapies in Health and Medicine [8]. It has no control arm and no randomisation.

For GHK-Cu, the human record is topical and dermatological rather than injectable, and is discussed in the review literature [15][16][17] rather than resting on indexed controlled injectable trials. For KPV, no controlled human trial has been located.

Rodent studies

BPC-157 has a large rodent literature. Chang and colleagues reported in 2011 in the Journal of Applied Physiology on tendon outgrowth, cell survival and cell migration in a rat tendon model [6]. Vuksic and colleagues reported in Surgery Today in 2007 on ileoileal anastomosis in the rat [7]. The wider body of rodent work is summarised in review form by Seiwerth and colleagues [5] and by Józwiak and colleagues in a 2025 literature and patent review [4].

For GHK-Cu, Fu and colleagues reported in the Journal of Orthopaedic Research in 2015 on a rat model of anterior cruciate ligament reconstruction, describing the healing outcome as transiently improved [18] — the qualifier is the authors’ own and is retained here.

For KPV, Dalmasso and colleagues reported in Gastroenterology in 2008 on PepT1-mediated uptake of the tripeptide and intestinal inflammation in murine models [20]. Xiao and colleagues reported in Molecular Therapy in 2017 on orally targeted delivery of KPV via hyaluronic acid-functionalised nanoparticles in a murine ulcerative colitis model [21]. Getting and colleagues dissected the contributions of the core and C-terminal KPV portions of α-melanocyte-stimulating hormone in murine models in 2003 [22]. Shao and colleagues reported in 2021 on a mucoadhesive hydrogel carrying KPV in chemotherapy-induced oral mucositis [24].

In vitro studies

Siméon and colleagues reported in Life Sciences in 2000 that the GHK-Cu complex stimulated matrix metalloproteinase-2 expression in fibroblast cultures [19]. Elliott and colleagues examined α-melanocyte-stimulating hormone, the KPV fragment and adrenocorticotropic hormone signalling in human keratinocyte cell cultures, published in the Journal of Investigative Dermatology in 2004 [23].

Review and commentary literature

Two 2026 reviews address these compounds together in the context of musculoskeletal and sports medicine. Mendias and Awan reviewed approved and unapproved peptide therapies in Sports Medicine, covering BPC-157 and TB-500 among others, and characterised rigorous human safety data for the unapproved compounds as scarce [1]. Mayfield and colleagues published a primer on injectable peptide therapy in the American Journal of Sports Medicine [2].

Evidence gaps and limitations

Stated plainly, and without softening:

• There is no controlled trial of this combination in any species. Not in humans, not in animals. The four peptides have never been studied together in the published record.
• The single co-administration study that exists covers two of the four, in rats, and reported no additional benefit from combining them over either given alone [3]. That is the only direct experimental evidence bearing on combination at all, and it does not support an assumption that combining these peptides is additive.
• There is no pharmacokinetic data for the four given together, and no interaction data of any kind — pharmacokinetic, pharmacodynamic or chemical.
• There is no published stability study of the four co-formulated in one vial. The presence of a redox-active copper complex alongside three other peptides is a formulation question the literature has not addressed.
• BPC-157 has no published randomised controlled trial in humans for any indication. The phase II inflammatory bowel disease work referenced in the review literature has not been published. The one indexed human report is uncontrolled [8].
• The BPC-157 preclinical literature is heavily concentrated in a single research group. A substantial proportion of the primary rodent work, and of the reviews summarising it, originates from the same Zagreb-based collaboration. That is a structural feature of the evidence base and independent replication is correspondingly limited.
• The thymosin β4 human trial base does not transfer to TB-500. The trials at [9] through [13] used a 43-residue protein. TB-500 is a 7-residue fragment. Treating the trial base of one as evidence about the other is a category error, and it is a common one.
• GHK-Cu human evidence is topical, not injectable. Its use as a cosmetic ingredient applied to skin generates a body of dermatological data that says nothing about parenteral administration.
• KPV has no controlled human trial at all. Its record is murine and in vitro.
• Blend composition is undeclared by the designation. “KLOW” specifies four names and no ratio. Two preparations bearing the name are not necessarily the same material, and no analysis of one is transferable to another.

Regulatory and standards position

Marketing authorisation

None of the four components holds a marketing authorisation as a medicinal product in the United Kingdom (MHRA), the European Union (EMA) or the United States (FDA). None is an authorised medicine in any of those jurisdictions in any formulation, and the blend as a blend is not an authorised product anywhere.

Under the Human Medicines Regulations 2012, and consistently with MHRA Guidance Note 8, a product may fall within the definition of a medicinal product either by function or by presentation. The presentation limb turns on the claims made about a product rather than on its chemistry, following the reasoning in Ter Voort (C-219/91). Materials of this class are supplied for laboratory research use only.

Controlled-drug status

None of BPC-157, TB-500, GHK-Cu or KPV is a controlled drug under the Misuse of Drugs Act 1971 or scheduled under the Misuse of Drugs Regulations 2001. No Home Office licence arises from their control status, and no export restriction applies on that basis.

WADA Prohibited List — the components sit in different classes

This is the point on which a single answer for the blend would be wrong. The 2026 WADA Prohibited List, in effect from 1 January 2026, names two of the four components, and it names them in different sections with different consequences.

BPC-157 appears in S0. The section covers “any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use”, and states that the class “covers many different substances including but not limited to BPC-157, 2,4-dinitrophenol (DNP), ryanodine receptor-1-calstabin complex stabilizers … and troponin activators”. The S0 heading states that all prohibited substances in that class are Specified Substances.

TB-500 appears in S2.3. The list of growth factors and growth factor modulators includes the entry “Thymosin-ß4 and its derivatives e.g. TB-500”, alongside fibroblast growth factors, hepatocyte growth factor, IGF-1, mechano growth factors, PDGF and VEGF. The subsection closes with a sweep covering “other growth factors or growth factor modulators affecting muscle, tendon or ligament protein synthesis/degradation, vascularisation, energy utilization, regenerative capacity or fibre type switching”. The S2 heading states that all prohibited substances in that class are non-Specified Substances.

The Specified/non-Specified distinction is not cosmetic. Under Article 4.2.2 of the World Anti-Doping Code, the classification governs the sanctioning framework applied to an adverse analytical finding. The List records the comment to that article: Specified Substances “should not in any way be considered less important or less dangerous than other doping substances”, but are “simply substances and methods which are more likely to have been consumed or used by an Athlete for a purpose other than the enhancement of sport performance”. A single vial containing both BPC-157 and TB-500 therefore contains one Specified and one non-Specified prohibited substance, which are handled differently.

GHK-Cu and KPV are not named anywhere on the 2026 List, and do not appear in its index. Two provisions on the List are open-ended and are drafted to capture substances not individually named: the S0 definition, which is keyed to the absence of approval by any governmental regulatory health authority for human therapeutic use rather than to a list of names, and the closing sweep of S2.3 quoted above. Neither GHK-Cu nor KPV holds approval for human therapeutic use in the United Kingdom, the European Union or the United States. Determinations of prohibited status in an individual case are made by the relevant anti-doping organisation, not by the substance’s absence from an index.

United States compounding position

The FDA placed BPC-157 in Category 2 of its interim policy on compounding using bulk drug substances under section 503A of the Federal Food, Drug, and Cosmetic Act, in 2023. Category 2 covers substances nominated with sufficient supporting information for the agency to evaluate but which raise significant safety concerns; such substances may not be used in compounding unless the FDA publishes a final rule or Federal Register notice authorising the particular substance.

On 23 July 2026 the FDA’s Pharmacy Compounding Advisory Committee voted in favour of recommending BPC-157 and KPV for inclusion on the 503A bulks list, reported as 8 votes to 6 with one abstention. That vote is a recommendation from an advisory committee. It is not a decision of the agency, it is not binding on the agency, and it is not a marketing authorisation or an approval of either substance as a medicine. Any change to compounding eligibility would require the FDA to complete formal notice-and-comment rulemaking.

Cosmetic ingredient status of GHK-Cu

GHK-Cu is used as a cosmetic ingredient under the INCI name Copper Tripeptide-1 and is permitted for cosmetic use in the European Union and the United Kingdom, subject to product-level safety assessment under the applicable cosmetics regulation. Cosmetic ingredient status concerns topical application in a cosmetic product. It is not a medicines authorisation and carries no implication for any other route or purpose.

Laboratory handling and safety

No complete toxicological dossier exists for any of the four components, and none exists for the blend. In the absence of such data, the material should be handled as a research chemical of incompletely characterised hazard.

• Handle in a designated laboratory area by trained personnel, under a COSHH assessment appropriate to a substance of unknown toxicity.
• Nitrile gloves, safety spectacles and a laboratory coat. Weigh lyophilised solid in a manner that controls dust; avoid generating aerosols of the powder or of reconstituted solution.
• The copper content of the GHK-Cu component means the material is not a pure organic peptide preparation. Copper salts are irritant, and the assessment should treat the preparation as containing a transition metal compound.
• Where a vial is opened, use appropriate aseptic technique; the lyophilate is not preserved and the preparation is not manufactured to a sterility standard applicable to a medicinal product.
• Dispose of surplus material, reconstituted solution and contaminated consumables through the appropriate laboratory chemical waste stream, taking account of the copper content, and not to drain or general waste.
• Sharps used for reconstitution or transfer go to a sharps container.
• Label reconstituted solutions with the identity, total concentration, the diluent used and the date of reconstitution. For a blend, record the declared component ratio at the same time; it is not recoverable from the solution by inspection.

References

1. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Medicine, 2026; online ahead of print. Model: review. PMID 41966639
2. Mayfield CK, Bolia IK, Feingold CL, Lin EH, Liu JN, Rick Hatch GF, Gamradt SC, Weber AE. Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians. American Journal of Sports Medicine, 2026; 54(1):223–229. Model: review. PMID 41476424
3. Biçer O, Adanir O, Güleryüz Y, Balci EC, Dinçel YM, Yenigün MY, Aydin C, Bayrak BY. Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study. Joint Diseases and Related Surgery, 2026; 37(3):822–837. Model: rodent (Sprague-Dawley rat), four arms including a BPC-157 + TB-500 combination arm. PMID 42542926
4. Józwiak M, et al. Multifunctionality and Possible Medical Application of the BPC 157 Peptide — Literature and Patent Review. Pharmaceuticals (Basel), 2025; 18(2). Model: review. PMID 40005999
5. Seiwerth S, et al. Stable Gastric Pentadecapeptide BPC 157 and Wound Healing. Frontiers in Pharmacology, 2021; 12:627533. Model: review. PMID 34267654
6. Chang CH, et al. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. Journal of Applied Physiology (1985), 2011; 110(3):774–780. Model: rodent (rat) and in vitro. PMID 21030672
7. Vuksic T, Zoricic I, Brcic L, Sever M, Klicek R, Radic B, Cesarec V, Berkopic L, Keller N, Blagaic AB, Kokic N, Jelic I, Geber J, Anic T, Seiwerth S, Sikiric P. Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia) heals ileoileal anastomosis in the rat. Surgery Today, 2007; 37(9):768–777. Model: rodent (rat). PMID 17713731
8. Lee E, et al. Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain. Alternative Therapies in Health and Medicine, 2021; 27(4):8–13. Model: human, uncontrolled. PMID 34324435
9. Wang X, et al. A first-in-human, randomized, double-blind, single- and multiple-dose, phase I study of recombinant human thymosin β4 in healthy Chinese volunteers. Journal of Cellular and Molecular Medicine, 2021; 25(17):8222–8228. Model: human trial, phase I randomised. PMID 34346165
10. Sosne G, et al. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea, 2015; 34(5):491–496. Model: human trial, phase 2 randomised. PMID 25826322
11. Ruff D, et al. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Annals of the New York Academy of Sciences, 2010; 1194:223–229. Model: human trial, phase I randomised. PMID 20536472
12. Guarnera G, et al. The effect of thymosin treatment of venous ulcers. Annals of the New York Academy of Sciences, 2010; 1194:207–212. Model: human trial, phase 2 randomised. PMID 20536470
13. Guarnera G, et al. Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing. Annals of the New York Academy of Sciences, 2007; 1112:407–412. Model: human trial, randomised. PMID 17495250
14. Goldstein AL, et al. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opinion on Biological Therapy, 2012; 12(1):37–51. Model: review. PMID 22074294
15. Pickart L, et al. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences, 2018; 19(7). Model: review. PMID 29986520
16. Pickart L, et al. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International, 2015; 2015:648108. Model: review. PMID 26236730
17. Pickart L. The human tri-peptide GHK and tissue remodeling. Journal of Biomaterials Science, Polymer Edition, 2008; 19(8):969–988. Model: review. PMID 18644225
18. Fu SC, et al. Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction. Journal of Orthopaedic Research, 2015; 33(7):1024–1033. Model: rodent (rat). PMID 25731775
19. Siméon A, et al. The tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ stimulates matrix metalloproteinase-2 expression by fibroblast cultures. Life Sciences, 2000; 67(18):2257–2265. Model: in vitro (fibroblast culture). PMID 11045606
20. Dalmasso G, et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology, 2008; 134(1):166–178. Model: rodent (mouse) and in vitro. PMID 18061177
21. Xiao B, et al. Orally Targeted Delivery of Tripeptide KPV via Hyaluronic Acid-Functionalized Nanoparticles Efficiently Alleviates Ulcerative Colitis. Molecular Therapy, 2017; 25(7):1628–1640. Model: rodent (mouse). PMID 28143741
22. Getting SJ, et al. Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides. Journal of Pharmacology and Experimental Therapeutics, 2003; 306(2):631–637. Model: rodent (mouse). PMID 12750433
23. Elliott RJ, et al. alpha-Melanocyte-stimulating hormone, MSH 11-13 KPV and adrenocorticotropic hormone signalling in human keratinocyte cells. Journal of Investigative Dermatology, 2004; 122(4):1010–1019. Model: in vitro (human keratinocyte culture). PMID 15102092
24. Shao W, et al. In situ mucoadhesive hydrogel capturing tripeptide KPV: the anti-inflammatory, antibacterial and repairing effect on chemotherapy-induced oral mucositis. Biomaterials Science, 2021; 10(1):227–242. Model: rodent. PMID 34846053

Chemical identity data are drawn from PubChem (CIDs 9941957, 62707662, 73587, 165429100, 71587328 and 125672). Anti-doping classifications are quoted from the World Anti-Doping Code International Standard Prohibited List 2026, in effect 1 January 2026.

Research use only

KLOW is supplied strictly as a laboratory chemical for research use only. It is not a medicinal product, it holds no marketing authorisation in any jurisdiction, and it is not authorised for human or veterinary use. It is not for administration to humans or animals, not for diagnostic use, not for therapeutic use, and not for use in food or cosmetics.

Nothing in this entry is a statement that any of these compounds treats, prevents, cures or improves any condition, and nothing here should be read as guidance on administration. The studies summarised above are described as a record of what has been published and of the models in which it was investigated. Findings reported in an animal or in vitro study are findings about that model. Purchasers are responsible for compliance with all applicable legislation governing possession, handling, use and disposal in their jurisdiction, and for institutional approval where required.