My take on this based off anecdotal experience and some research.
Pharmacologically speaking, most alternative cannabinoids at comparative potencies to THC (0.3x-1.5x) are so similar to D9 THC, that i can confidently say the research on D9 alone is enough to warrant these others at least as safe as D9 THC.
Most of these plant-occurring/natural cannabinoids have been explored/researched extensively in humans, and other animals, both Vitro, and Vivo for nearly 90 years. Delta 8 THC (previously known in research as Delta 6 THC or D6 THC) has been discovered around 1940-1941.
As a matter of fact, since some of these cannabinoids have lower potencies, and are only partial or full agonists of the same CB1 and CB2 receptors just like regular cannabis, the effect and risks are essentially the same, but because of the lesser binding to these sites, it’s less strong – higher number ki)- please note that this is only applicable for noids of similar potency.
Some potent synthetic (not naturally occurring) and natural cannabinoids are extremely potent can be extremely dangerous if handled or used improperly, you could experience seizures, anxiety and stress, psychosis, internal and external hallucinations and much worse.
With more regulation and less of war on drugs, all this could be made even safer, since it’s not necessarily just the pharmacokinetics of a bioactive chemical that causes toxicity. Byproducts and residual solvents or reagents could still end up in your end product, and with some companies not taking it seriously enough, it has happened before where have gotten very ill or even died as a result of this.
Let me know what you think, and correct me or fill me in if you want! cheers