By Laureen J. Marinetti, PhD, F-ABFT

BTMPS (Bis[2,2,6,6-tetramethyl-4-piperidyl] sebacate), brand name Tinuvin®770, is commonly used in the manufacture of plastics as a UV-stabilizing additive to prevent degradation from sunlight and weather exposure. BTMPS was first identified in the U.S. illicit drug market in mid-2024 and spread rapidly across the country. The first identifications were by community drug checking organizations which identified BTMPS using Fourier Transform Infrared spectroscopy (FTIR). BTMPS is not the only impurity that may be found in the drug supply about which little is known, and not even the only light stabilizer normally used in manufacturing. For example, 2,2,6,6-tetramethyl-4-piperidinol has also been detected, but not in the quantities observed for BTMPS.

BTMPS is often found in samples alongside fentanyl, synthetic opioids, and stimulants, and sometimes at a greater concentration than the illicit drug. BTMPS’s appearance coincided with disruptions in the usual drug supply chain and reports of unusual odors and tastes in samples. BTMPS does not produce a “high” or any known psychoactive effects in humans. It may be used as a bulking agent to increase volume for profit or potentially to stabilize other chemical precursors.

Chemical Structure of BTMPS drawn by Kevin G. Shanks (2026)

BTMPS is not approved or studied for human use. Animal studies suggest potential cardiotoxicity, ocular damage, neurotoxicity, and sudden death. The safety data sheet for BTMPS states that human exposure can result in eye damage and skin irritation. BTMPS is a potent calcium channel blocker and nicotine receptor antagonist, which may enhance the toxicity of cooccurring substances.

Axis has confirmed one positive case with BTMPS in a blood sample. The case was an oxycodone overdose with a very high concentration of oxycodone and no illicit drugs detected. It is possible that the BTMPS was a contaminant on the oxycodone pills from the plastic medication bottle, and because so many of them were ingested at one time, the BTMPS accumulated to a detectable concentration. In the Washington drug detection data, it was found that in the following potential licit drug samples, BTMPS was detected. In 296 prescription opioid samples, 3.4% were positive for BTMPS, and in 163 samples sold as M30s (prescription oxycodone) or Percocet, 3.7% were positive for BTMPS.

BTMPS likely ended up in the illicit drug supply because it is cheap, readily available, and possibly introduced through contaminated precursor chemicals or manufacturing streams. It provides no known benefit to users and may increase health risks due to its toxicological profile. Axis monitors BTMPS in the Novel Emerging Compounds (NEC) panel (order code 13710) and Comprehensive Panel, Blood with Analyte Assurance™ (order code 70510) using liquid chromatography with quadrupole time of flight mass spectrometry (LC-QToF-MS).  

If you have questions about BTMPS and how it may play a role in your medical-legal investigation, please reach out to Axis subject matter experts by email ([email protected]) or phone (317-759-4869, Option 3).

References

• UV Stabilizer BTMPS in the Illicit Fentanyl Supply in 9 US Locations, Letter, Journal of the American Medical Association, February 5, 2025.
• Where do we see BTMPS?, Addictions, Drug and Alcohol Institute, University of Washington, https://adai.washington.edu/WAdata/DrugChecking/BTMPS.html, 2025.