Why is it dangerous to pets?
5-HTP raises serotonin directly and is one of the supplements most often reported to cause serious poisoning in dogs — tremors, seizures and serotonin syndrome.
St John’s wort, ephedra, guarana and bitter orange (synephrine) act like antidepressants or stimulants. Because supplements are unregulated, the actual content can be far above what the label says.
Why speed matters
Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.
Symptoms of herbal-supplements poisoning
- Agitation, restlessness, confusion
- Tremors, twitching, rigidity
- Fast heart rate, panting, high temperature
- Vomiting, diarrhoea
- Seizures, collapse (emergency)
What to do right now
- Call your vet or a poison line and read the ingredient list aloud.
- Bring the bottle — “proprietary blend” labels often hide stimulants.
- Do not give any other supplement or medicine to calm the pet.
- Keep all supplements in a closed cabinet, treat them exactly like prescription drugs.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.
Sources & further reading
- ASPCA Animal Poison Control — pet poison database & dosage references
- Pet Poison Helpline — toxicology triage guidelines
- Merck Veterinary Manual — toxicology monographs
- Vets Now (UK) — emergency toxicosis guidance