7-Hydroxymitragynine Facts
Opioid;
Description
7-Hydroxymitragynine (7-HMG) — 7-OH — is a semi-synthetic opioid of the monoterpenoid indole alkaloid class. It activates opioid receptors in the brain, producing pain suppression, sedation, and euphoria.
Subjective effects include pain relief, sedation, euphoria, and anxiolysis. The experience is defined by what it removes: discomfort recedes, and body and mind settle into heavy calm.
7-HMG produces physical dependence and opioid withdrawal; respiratory depression 4.5 times more potent than morphine[1] makes breathing failure the primary lethal risk. Tolerance is shared bidirectionally with morphine,[2] and combining with any other depressant sharply amplifies the risk of fatal breathing failure.
Dose and durationby route · individual sensitivity varies
No dose recorded for this route. The timings are not a dose guide.
Starts in 20 – 45 minLasts 4 – 8 hoursAfter-effects 6 – 24 hours
Body and dependence
- Acute toxicity
- High
- Chronic toxicity
- Moderate
- Physical dependence
- High
- Psychological dependence
- High
- Withdrawal
- Severe · medical supervision
- Compulsive redosing
- High
Tolerance
- Builds
- Moderate
- Fully resets after
- Not recorded
- Carries over to
- morphine;
mu-opioid agonists (class)
Effectslikely at a common dose
- Perception
- none likely · 4 possible, including Spatial disorientation, Visual acuity suppression, Visual haze / noise
- Body
- Body high;
Muscle relaxation; Pain suppression; Pupil constriction; Sedation; +17 possible, including Nausea, Dizziness, Motor control impairment - Thinking
- none likely · 12 possible, including Analysis suppression, Cognitive impairment, Compulsive redosing urge
- Feeling
- Euphoria;
+2 possible - Self
- none likely · 3 possible, including Craving, Social disconnection
- Time
- none likely · 2 possible, including Temporal disorientation
- Awareness
- none likely · 1 possible
Who shouldn't take it
Combinations60 recorded
Seek help immediately if
- Unresponsive / can't be woken, even to a firm sternal rub
- Slow, shallow, or stopped breathing
- Pinpoint pupils
- Blue/grey lips, fingertips, or skin (cyanosis)
- Limp body; pale, clammy skin
- Choking or gurgling sounds ("death rattle")
- Slow, erratic, or absent pulse
What to do
- Try to wake them — shout their name, firm sternal rub
- Call emergency services immediately
- Administer naloxone if available
- Give rescue breaths (or CPR if there is no pulse)
- Place them in the recovery position
- Stay with them; re-dose naloxone every 2–3 minutes if there is no response
- Reversal agent
- Naloxone (Narcan) — opioid antagonist. May require repeated doses; its effect can wear off before the opioid does.
With prompt naloxone and rescue breathing, reversal is usually rapid. Because naloxone can wear off before the opioid — especially with long-acting opioids (methadone) or high-potency ones (fentanyl) — a period of monitoring is needed even after the person revives.
988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE
References
- [1]^Zuarth Gonzalez JD, Ragsdale AK, Mukhopadhyay S, McCurdy CR, McMahon LR, Obeng S, Wilkerson JL (2025) Mitragynine and 7-hydroxymitragynine: Bidirectional effects on breathing in rats. — Journal of Pharmacology and Experimental Therapeutics doi:10.1016/j.jpet.2025.103720
- [2]^Matsumoto K, Horie S, Takayama H, Ishikawa H, Aimi N, Ponglux D, Murayama T, Watanabe K (2005) Antinociception, tolerance and withdrawal symptoms induced by 7-hydroxymitragynine, an alkaloid from the Thai medicinal herb Mitragyna speciosa. — Life Sciences PMID:16169018