Bioenergetic

5-Amino-1MQ is a small-molecule inhibitor of nicotinamide N-methyltransferase (NNMT), an enzyme that is more active in the fat and liver of obese mice. In obese mice, injections reduced body weight and fat without lowering food intake. In old mice they improved muscle repair and grip strength. No study has given it to people, and nearly all of the published work comes from one group linked to the company developing it.

Acetyl-L-carnitine (ALCAR) is the acetyl ester of L-carnitine and the body's main carnitine ester. It is sold as a supplement and, in some countries, as a prescription drug. Meta-analyses find that it eases depressive symptoms, mostly in older adults and across small, inconsistent trials, and that it reduces diabetic nerve pain at doses above 1.5 g a day, on very low-certainty evidence. It did not slow Alzheimer's disease in two year-long trials, and it made chemotherapy nerve damage worse in a large one.

Creatine is one of the most researched sports supplements. It is best known for building strength and muscle, and is increasingly studied for the brain. Meta-analyses of randomized trials find small-to-moderate improvements in memory, attention and processing speed. The effects on memory are largest in older adults. It is well tolerated at 3 to 5 g a day.

ITPP is a synthetic phosphate derivative of inositol that gets inside red blood cells and makes hemoglobin let go of its oxygen more readily, so more oxygen reaches tissue that is short of it. It was developed as a cancer drug, to relieve tumor hypoxia, and has been through one phase Ib trial in 28 patients that established a maximum tolerated intravenous dose. Its reputation as a performance drug rests on a single 2009 mouse study in which it raised maximal exercise capacity by up to 57%; nothing like that has been tested in people, and anti-doping laboratories screen urine for it.

Mitochonic Acid 5 (MA-5) is a synthetic indole compound studied for mitochondrial disease. It binds mitofilin/MIC60, a protein involved in organizing the inner mitochondrial membrane. Human development has reached phase I safety testing; clinical benefit remains unproven.

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell. It carries electrons in energy metabolism and is used up by sirtuins, PARPs and CD38. Clinics sell it as an intravenous drip, but no trial has tested NAD+ infusions for any health outcome. In a small study, infused NAD+ disappeared from the blood for the first 2 hours. Most human data come from its oral precursors NR and NMN. They reliably raise NAD+, but their effects on health outcomes are mixed and often null.