STS-135 (drug)


STS-135, also known as 5F-APICA, represents a designer drug available through online vendors, positioned as a cannabimimetic agent. While the origins of its design remain unclear, STS-135 appears to leverage insights into structure-activity relationships within the indole class of cannabimimetics. It serves as the terminally-fluorinated counterpart to SDB-001, mirroring the relationship between AM-2201 and JWH-018, as well as XLR-11 and UR-144. In vitro, STS-135 acts as a potent agonist of cannabinoid receptors, exhibiting an EC50 of 51 nM for human CB2 receptors and 13 nM for human CB1 receptors. Notably, STS-135 has been shown to induce bradycardia and hypothermia in rats when administered at doses ranging from 1 to 10 mg/kg, indicating cannabinoid-like effects.

IUPAC name
CAS Number1354631-26-7
PubChem CID57404059
CompTox Dashboard (EPA)DTXSID40725427
Chemical and physical data
Molar mass382.523 g·mol−1

Legal status

In October 2015, China classified STS-135 as a controlled substance, and it is likewise prohibited in the United Kingdom.


Detection of STS-135 is feasible using a forensic standard, and this compound has been documented on the Forendex website, which lists potential drugs of abuse.


1. What is STS-135?

  • STS-135 is a synthetic cannabinoid, also known as 5F-APICA, designed to mimic the effects of cannabinoids.

2. Is STS-135 legal to use or possess?

  • No, STS-135 is classified as a controlled substance in certain countries, such as China, and is illegal in the United Kingdom. Its legality varies by jurisdiction, so it’s crucial to check local laws and regulations regarding its possession and use.

3. How does STS-135 work?

  • STS-135 acts as a potent agonist of cannabinoid receptors, specifically CB1 and CB2 receptors. It exerts its effects by binding to these receptors in the brain and body, producing cannabinoid-like responses.

4. What are the effects of STS-135?

  • STS-135 is designed to replicate the effects of natural cannabinoids, potentially leading to altered perception, relaxation, and other psychoactive effects. It is essential to note that the results can vary and may come with health risks.

5. Is STS-135 safe for use?

  • The safety of STS-135 is a matter of concern, as with many synthetic cannabinoids. They can be unpredictable and carry potential health risks. The use of unregulated designer drugs like STS-135 is discouraged.

6. How can STS-135 be detected or identified?

  • Forensic professionals have developed standards for detecting STS-135. It has been listed on the Forendex website as a resource for identifying potential drugs of abuse.

7. Where can I find more information about STS-135?

  • To learn more about STS-135, its effects, and its legal status, refer to credible sources, including government health agencies, substance abuse resources, and scientific literature. Always rely on accurate and up-to-date information.


  1. In 2015, Wilkinson SM, Banister SD, and Kassiou delved into the clandestine design of synthetic cannabinoids, exploring the use of bioisosteric fluorine. Their study, published in the Australian Journal of Chemistry, reveals insights into this secretive world of synthetic drug development.
  2. Banister SD and a team of researchers conducted a comprehensive investigation into the impact of bioisosteric fluorine in a range of synthetic cannabinoid designer drugs. The study, featured in ACS Chemical Neuroscience, covers compounds like JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135, providing valuable insights into the effects of fluorine substitutions.
  3. In China, significant regulatory changes took place concerning non-medical narcotics and psychotropic substances. On September 27, 2015, the China Food and Drug Administration released a notice regarding the management of these substances, signifying a pivotal moment in drug control.
  4. The Southern Association of Forensic Scientists serves as a reputable resource in the field of forensics, contributing to advancements in the detection and analysis of substances, including designer drugs.

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