If you have any reason to suspect your pet has ingested something toxic, please contact your veterinarian or one of the other resources listed:
ASPCA Animal Poison Control Center 24-hour hotline at (888) 426-4435
• Pet Poison Helpline® 24-hour animal poison control service at (855) 764-7661


5-HTP, or Griffonia seed extract, is a human dietary supplement used for a variety of ailments in humans. This supplement is potentially toxic in pets as it has the ability to induce serotonin syndrome.


Signs and symptoms of toxicity: sedation, agitation, tremors, seizures, hyperthermia, GI upset, difficulty walking, abdominal pain, increased sensitivity to stimuli, and temporary blindness.

Toxic consumption: For dogs, the minimum oral toxic dose is 24 mg/kg (11 mg/lb). Oral ingestion of 128 mg/kg (58 mg/lb) by a dog may be fatal.

Dogs: 5-HTP Toxic Consumption
Yorkie, Chihuahua
Pug, Boston Terrier, Poodle
Beagle, Scottish Terrier
Boxer, Cocker Spaniel
Retriever, German Shepherd
Great Dane, St. Bernard
1 – 10 lbs.
(0.45 – 4.6 kg)
11 – 25 lbs.
(5 – 11.4 kg)
26 – 40 lbs.
(11.8 – 18.2 kg)
41 – 70 lbs.
(18.6 – 31.8 kg)
71 – 90 lbs.
(32.3 – 40.9 kg)
91 – 110 lbs.
(41.4 – 50 kg)
dog1 dog2 dog3 dog4 dog7 dog6
> 10.8 mg > 120 mg > 283 mg > 446 mg > 775 mg > 993 mg

– Peterson, M.E. & P.A. Talcott (2013). Small Animal Toxicology, 3rd Ed., Saunders. St. Louis.

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