An isomer refers to each of at least two molecules that have the same constituent atoms but that have different arrangements of atoms—such as different bonding, shape, or orientation of atoms. Delta-8 THC is an isomer of delta-9 THC, which makes delta-8 THC subtly different than delta-9 THC.
Delta-8 THC binds to the CB1 and CB2 receptors . The National Cancer Institute suggests that delta-8 provides relief from nausea, pain and anxiety, as well as neuroprotection for the aging brain . Delta-8 THC is psychoactive, but less psychoactive delta-9 THC. One study suggested that delta-8 has about two-thirds of the potency of delta-9 THC .
In a 1995 study  in Jerusalem led by Dr. Raphael Mechoulam, 8 pediatric patients with cancer were given delta-8 THC to test whether delta-8 would prevent vomiting from antineoplastic therapy. The patients were treated with a variety of anticancer drug protocols. Researchers found that the children could be administered doses of delta-8 THC that were considerably higher than the doses of delta-9 THC generally administered to adult cancer patients, and without the occurrence of major side effects (5-10 mg/m2 of delta-9 THC for adult patients versus 18 mg/m2 of delta-8 THC used in Mechoulam’s study in children).
Success rates were 100%, regardless of the cancer protocol used. The total number of treatments was 480 (the 8 patients were treated during a 2-year period). Mechoulam concluded that the complete success in preventing vomiting due to antineoplastic treatment in children (with very few, mild side effects) suggested that delta-8-THC might offer a new, inexpensive antiemetic agent in pediatric cancer chemotherapy.
A study completed in 1975  at the National Cancer Institute found that delta-8 THC (as well as delta-9 THC and CBN) had the ability to stop tumor growth. A study in mice published in 2004 found that low doses (.001mg/kg) of delta-8 caused increased food consumption and tendency to improve cognitive function, without the side effects typically associated with THC.
These studies suggest that low doses of delta-8 THC can help treat nausea, eating disorders, and cachexia .
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