On August 18, the Department of Defense (DoD) issued a memorandum marking a new direction in its drug testing policy. Beginning on October 1, 2025, psilocin will be added to the military’s drug testing program. Officials framed the move as necessary to address “emerging drug threats,” endangering readiness, discipline, and security.
For decades, the military has operated a large-scale drug testing program, collecting millions of urine samples each year. Tests normally focus on substances like marijuana, cocaine, amphetamines, and opioids. Commanders have always had the authority to order additional testing when they had probable cause, and specialized laboratories could look for less common substances – including hallucinogens – if requested. The August memo is significant because psilocin is now being added to the standard test panel rather than being left as a substance that units seek out in rare cases. In other words, the drug is moving from the category of “only if suspected” into “we will look whenever the capacity exists.”
Psilocybin has caused debate as research expands into potential medical uses, especially for depression and post-traumatic stress disorder, conditions prevalent among service members and veterans. Several states – Colorado, Oregon, and New Mexico – have decriminalized the substance in therapeutic settings, but it remains a Schedule I controlled substance under federal law. This cultural shift raises the likelihood servicemembers will encounter and experiment with the drug, especially when stationed in states with relaxed laws. The DoD is sending a clear message: regardless of whatever civilian law may permit, psilocin/psilocybin is banned for military personnel. The situation is similar to marijuana, which remains a prohibited substance for troops even though it is legal in many states.
Understanding how psilocybin and psilocin work shows both why the military is concerned and why testing is challenging. Psilocybin itself is inactive; once ingested, the body converts it to psilocin, which interacts with serotonin receptors in the brain to produce hallucinations and mood changes. Psilocin clears the body quickly, with a half-life of only a few hours. Since most of it is broken down and excreted within a day, catching its use requires sensitive testing methods like mass spectrometry. Even still, the detection window is much shorter than for substances such as cannabis, which can linger in the body for weeks. This raises an obvious question: why commit the funding and lab resources to expand testing for a drug capable of disappearing before the weekend is over?
The DoD already tests for substances that leave the body quickly, such as cocaine, but these are different. Many other substances carry a high risk of dependence, and users often take them repeatedly, even doing so multiple times within the same day. This behavior pattern makes testing worthwhile even with a narrow detection window. Psilocin does not generally present the same problem. It is not considered addictive, and most use occurs in isolated sessions rather than daily binges. This raises the question of why the Pentagon would allocate funding to this issue when detection could be difficult to obtain on the next duty day.
The memo also mentions “cutoff concentrations,” which are the laboratory thresholds separating a positive result from a negative one. These levels help prevent someone from being flagged for trivial amounts or accidental exposure. The Pentagon has not released the specific cutoff values for psilocin publicly, but the existence of such limits shows the results will depend on laboratory analysis rather than trace detection.
What does this change mean in practice? Psilocin officially becomes part of the DoD drug-testing program as of October 1, but the rollout will be gradual. At first, the DoD will focus on specimens collected because of probable cause, consent, or commander direction. These methods of collection have always been possible, but now those samples will be tested for psilocin as part of routine lab processing rather than requiring a special request. Over time, as laboratories expand their capacity, psilocin will eventually be included in random testing, just like marijuana or amphetamines. The memo makes clear the Pentagon’s intent is deterrence as much as punishment: by moving psilocin onto the official panel, the Department is signaling it will soon be as routine to test for as other prohibited substances.
The August 18 memo fits a broader pattern of military drug policy. The DoD adjusts its panels to reflect substances it believes pose a growing risk. In past years, synthetic cannabinoids and fentanyl analogues have been added after they appeared on the civilian market. Psilocin is the latest example of this logic.
For servicemembers, the practical lesson is straightforward. Even if psilocybin use is tolerated outside the gates in some states, it will not be allowed inside the ranks. The military has chosen to move psilocin from a rarely tested compound to one included in its standard toolkit. This is the real difference from past policy: not the possibility of testing, which always existed, but the likelihood that testing will actually happen.
