Detection of His-tagged Long-R³-IGF-I in a black market product. — VialBase Research

Summary

This is a forensic analytical case report, and it is the most directly actionable note in the IGF-1-LR3 set for anyone considering a purchase. The authors set the context plainly: performance-enhancing substances are illicitly used in elite and amateur sport and are often obtained from the black market because they are cheaper and easier to get, various studies have shown that black market products frequently do not contain the declared substances, and enormous quantities of illegally produced or imported drugs are confiscated from athletes and at customs with alarming analytical results. Against that backdrop they describe the identification of His-tagged Long-R³-IGF-I — a form usually produced for biochemical studies — in an injection vial. The ingredients were isolated by immunoaffinity purification and identified by nano-UPLC, high-resolution/high-accuracy mass spectrometry of both the intact and the trypsinated substance, and by an enzyme-linked immunosorbent assay. The tandem mass spectra characterised the protein as Long-R³-IGF-I with a His6-tag attached to the C-terminus by the linker amino acids Leu-Glu. The authors explain why that matters technically: His-tags are commonly added to proteins during synthesis to allow convenient and complete purification of the final product, and when attached to the N-terminus they are subsequently removed by specific enzymes. Here the tag remained. Their conclusion is unambiguous — the effects of His-tagged Long-R³-IGF-I in humans have not been elucidated or described, and the product may rather be a by-product from biochemical studies than something synthesized for injection purposes.

Key Findings

• A real black market injection vial was analysed and found to contain His-tagged Long-R³-IGF-I, a form normally produced for laboratory biochemical studies rather than for human administration
• Identification used immunoaffinity purification followed by nano-UPLC, high-resolution/high-accuracy mass spectrometry of the intact and trypsinated substance, and ELISA — the protein was characterised as Long-R³-IGF-I with a His6-tag attached to the C-terminus via Leu-Glu linker amino acids
• His-tags exist to simplify purification during synthesis; N-terminal tags are enzymatically removed afterwards, but the tag in this product was C-terminal and still present
• The effects of His-tagged Long-R³-IGF-I in humans have not been elucidated or described — an unstudied molecule was in an injectable vial
• The authors judge the vial may be a by-product from biochemical studies rather than material synthesized for injection purposes
• Framing context from the paper: black market products frequently do not contain the declared substances, and large volumes of illegally produced or imported drugs are seized with alarming analytical outcomes

Relevance to IGF-1-LR3

Anyone weighing a purchase of IGF-1-LR3 should read this one first. It is not a theoretical warning about counterfeits — investigators took an actual black market injection vial, ran it through immunoaffinity purification and high-resolution mass spectrometry, and found a research reagent: Long-R³-IGF-I still carrying a C-terminal His6-tag that a proper manufacturing process would either not use in that position or would remove. The tag is present because the material was made for lab convenience, not for injection into people. The authors state outright that the effects of His-tagged Long-R³-IGF-I in humans have never been elucidated or described, which means a buyer injecting that vial has no safety data at all — not thin data, none. Compounding this, there are no human trials of IGF-1 LR3 itself in this evidence set; all of the biological evidence is animal or in vitro. So the realistic risk is stacked twice over: an unapproved compound with no human trials, supplied through a channel demonstrated to deliver a different, entirely unstudied molecule than the one advertised.

Citation

Kohler M, Thomas A, Walpurgis K, et al. Detection of His-tagged Long-R³-IGF-I in a black market product. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society. 2010;20(5):386-90. doi:10.1016/j.ghir.2010.07.001.

See Also

• Parent compound: IGF-1-LR3