Most species of cactus are non-toxic. However, some contain toxins that can cause mild to moderate reactions when ingested. The sap of some species can irritate the skin, while other cacti contain psychoactive alkaloids. Cacti that cause mild irritation may not be considered poisonous, but it is important to take care when cultivating these species, especially in homes with pets and children.
Peyote (Lophophora williamsii)
The Peyote cactus is a small, spineless cactus found in the southwestern United States and Mexico. It contains psychoactive alkaloids, primarily mescalene, which have hallucinogenic effects when ingested. Consumption may also cause nausea, headaches, and dizziness. This cactus is considered unsafe to consume for both humans and pets.
Toxicity level: Moderate
Did you know? Peyote holds cultural and spiritual significance among indigenous communities in the southwestern United States and Mexico.
San Pedro (Echinopsis pachanoi)
The San Pedro cactus is a tall, columnar cactus found in the Andes mountains in South America. Similar to Peyote, it contains the psychoactive compound mescalene. Ingestion may cause hallucinations as well as digestive issues and dizziness.
Toxicity level: Moderate
Peruvian Torch
The Peruvian torch cactus is a tall, columnar cactus that is similar in appearance to San Pedro. Its toxicity also stems from mescaline, inducing hallucinogenic effects when ingested. Consumption may also cause digestive issues in humans and pets.
Toxicity level: Moderate
African Milk Tree (Euphorbia trigona)
Although this succulent is not a cactus, it can be mistaken for one. The African milk tree contains a toxic, milky sap that may cause skin irritation upon contact or digestive issues when ingested. Wear gloves when handling and take extra care to prevent the sap from coming into contact with the eyes.
Toxicity level: Mild
Barrel Cactus (Echinocactus spp. and Ferocactus spp.)
Barrel cacti are various, spherical or columnar species within the Echinocactus and Ferocactus genera. Some species contain bitter-tasting compounds in their flesh, sap, and skin. Although not highly toxic, ingesting large amounts can cause stomach upset or digestive issues. Handle these cacti with care to prevent potential skin irritation.
Toxicity level: Mild
Are Cactus Spines Poisonous?
Cactus spines are not poisonous but can be dangerous. Some species have sharp, hooked, or barbed spines that can cause damage—untreated puncture wounds may become infected. Some cacti produce a milky, latex-like sap that can be found in their spines. Although this sap is not toxic, contact may cause irritation or allergic reactions. Remove spines embedded in the skin and clean the wound with water and soap.
Tip: Always wear gloves when handling cacti or use newspaper as extra protection during repotting.
Most cacti are not toxic, although some may cause mild to moderate reactions and caution is advised when cultivating in the home. Consider which cacti are safe cats and dogs and note that even a non-toxic cactus may be dangerous with risks from spines and glochids. It is advisable to place most cacti out of reach from children and pets to avoid ingested reactions or injuries.
