Health officials are warning against the use of injectable peptide supplements and a potent synthetic opioid known as isotonitazene.

These substances represent a growing challenge for public health because they enter the market faster than regulators can track them. While one is marketed as a health booster and the other as a street drug, both are linked to severe health crises and death.

Isotonitazene, referred to on the street as ISO, has emerged as a significant threat in San Francisco. The San Francisco Health Department said the counterfeit opioid is 20 times [1] more potent than fentanyl. This extreme potency makes the drug attractive to dealers but increases the risk of fatal overdoses.

The first recorded death from isotonitazene in San Francisco occurred in April 2026 [4]. Other reports indicate the drug's potency can vary; one case involving the death of an 18-year-old [3] involved a synthetic opioid described as 10 times [2] stronger than fentanyl.

Azam Ahmed said synthetic drugs are evolving faster than the ability to regulate them [3]. This rapid evolution leaves users vulnerable to substances with unknown concentrations and effects.

Parallel to the opioid crisis, research is emerging regarding the use of injectable peptide supplements. These short-chain amino acids are often marketed as tools for health optimization, and performance enhancement. However, early research suggests these injectables may cause cancer and lead to early death [5].

Peptides are frequently promoted for various health benefits despite a lack of comprehensive safety data. The current research into their link to malignancy highlights the risks of using unregulated supplements that bypass traditional medical oversight [5].

“The killer counterfeit opioid isotonitazene, known on the streets as ISO, is 20 times more potent than fentanyl.”

The simultaneous rise of ultra-potent synthetic opioids and unregulated health supplements indicates a shift toward high-risk, chemically engineered substances. As the illicit market moves beyond fentanyl to even more potent analogs like isotonitazene, and the wellness market pushes unverified injectables, the burden on emergency medical services and long-term oncology care is likely to increase.