Lorcaserin, currently marketed under the trade name Belviq and previously Lorqess during development, is a weight-loss drug developed by Arena Pharmaceuticals. Lorcaserin is a selective 5-HT2C receptor agonist, and in vitro testing of the drug showed reasonable selectivity for 5-HT2C over other related targets. 5-HT2C receptors are located almost exclusively in the brain, and can be found in the choroid plexus, cortex, hippocampus, cerebellum, amygdala, thalamus, and hypothalamus. The activation of 5-HT2C receptors in the hypothalamus is supposed to activate proopiomelanocortin (POMC) production and consequently promote weight loss through satiety. This hypothesis is supported by clinical trials and other studies. While it is generally thought that 5-HT2C receptors help to regulate appetite as well as mood, and endocrine secretion, the exact mechanism of appetite regulation is not yet known. Lorcaserin has shown 100x selectivity for 5-HT2C versus the closely related 5-HT2B receptor, and 17x selectivity over the 5-HT2A receptor

Subitramine is a potent inhibitor of monoamines (serotonin, dopamine, noradrenaline) reuptake that was approved by FDA for the treatmen of obesity. Sibutramine is metabolized to metabolites M1 and M2 which are more active toward the monoamine transporters.The drug was withdrawn from the market because of clinical trial data indicating an increased risk of heart attack and stroke. It was sold under a variety of brand names including Reductil, Meridia and Sibutrex.

Clortermine hydrochloride (Voranil) is a non-amphetamine anorexigenic agent. Voranil, a sympathomimetic amine, is indicated for short-term adjunctive treatment of exogenous obesity. Its long duration of action permits once-a-day dosage. In a large number of patients studied, Voranil was found to be superior to placebo in weight reduction. Insomnia, dry mouth, palpitations and tachycardia have been reported in a small percentage of patients taking the drug. Voranil was originally developed by Ciba Pharmaceuticals Corporation and transferred to USV Pharmaceuticals Corporation in December 1971, as a result of a product exchange agreement.

Mazindol is an amphetamine-like medicine which was developed by Sandoz in 1967 and approved by FDA for the treatment of obesity and Duchenne muscular dystrophy under the names Sanorex and Mazanor. The exact mechanism of action is unknown, but possibly involves the stimulation of beta-adrenergic receptors and inhibition of monoamine reuptake. Both Sanorex and Mazanor were withdrawn from the market by reason other than safety. NLS Pharma now is developing mazindol for Attention Hyperactivity Disorder in adults (phase II).

Chlorphentermine exerts anorectic properties. It is a synthetic amphetamine derivatc claimed to have none of the excitatory effects of the parenit substanice. PRE-SATE (Chlorphentermine HCl) is an effective appetite suppressant with a pattern of pharmacologic action substantially different from those of traditional anorexigenics. In providing dependable appetite control with appreciable loss of bodyweight, PRE-SATE does not significantly increase central nervous system (CNS), cardiorespiratory or metabolic activity.

Phenmetrazine is an anti-obesity drug, which was discovered by Boehringer-Ingelheim in 1952 and approved by FDA under the name Preludin. Later on the drug was withdrawn from the market due to the reported cases of abuse. According to some studies, misuse of phenmetrazine turned many young addicts to crime. It is suggested that the drug exerts its effect by inhibiting the monoamine transport.

Cyclamic acid (Cyclamate) is banned in the United States but it is used in many other Western countries without safety concerns. Cyclamate interacts with the sweet taste receptor subunit T1R3 transmembrane domain. Initially it was recommended for use in treatment of obese patients and by individuals with diabetes but in August 27, 1970 FDA concluded that there was no substantial evidence of effectiveness of cyclamate compounds at any level for treatment of obese patients and individuals with diabetes and therefore prohibited continued sale of cyclamate containing products with drug labeling. cyclamate is the putative carcinogenic agent. Cyclamate was tested in the Maximal Electroshock Seizure model (mice, ip), showing moderate anticonvulsant activity.

Phenylpropanolamine belongs to the sympathomimetic amine class of drugs and is structurally related to ephedrine. The effects of phenylpropanolamine are largely the result of alpha-adrenergic agonist activity resulting from both direct stimulation of adrenergic receptors and release of neuronal norepinephrine. Phenylpropanolamine is mainly used as a nasal decongestant. Phenylpropanolamine is also used as anorexiant in obesity and to treat urinary incontinence in veteranary. Phenylpropanolamine containing products has been withdrawn by FDA due to the association of phenylpropanolamine use with increased risk of hemorrhagic stroke.

2,4-dinitrophenol (DNP) is a FDA-banned weight-loss agent and EPA-regulated environmental toxicant, traditionally used in research labs as an uncoupler of OXPHOS. Although not licensed for human consumption, DNP and DNP crystal form are used by bodybuilders and extreme dieters for their fat burning properties through inhibiting efficient energy (ATP) production in cells. Through uncoupling mitochondrial oxidative phosphorylation by facilitating proton transport across the mitochondrial membrane, DNP leads to rapid consumption of energy without generating ATP and consequently, to increased fat metabolism. However, the weight-loss effect comes with serious, and in some cases potentially fatal, adverse side effects, namely hyperthermia (the leading cause of fatality with acute DNP toxicity) and cardiac arrest, but also diaphoresis, tachycardia, tachypnea, skin toxicity, Fourier’s gangrene and cataracts with low dose chronic exposure. The proposed mechanism of DNP induced toxicity suggests the activation of ATP-sensitive K+ channels.

Oxedrine (Sympatol, p-synephrine) is a naturally occurring alkaloid molecule first appeared in Europe towards the end of the 1920s being sold as a drug under the brand name Sympatol. Oxedrine was then being prescribed as a remedy for a number of respiratory conditions, which include asthma, whooping cough, colds, and hay fever. More recently, synephrine gained popularity as a weight loss aid and it has become a favored component in the more popular brands of weight loss supplement stacks. This popularity can be attributed in part to the ban imposed on ephedra, to which it shares similar mechanisms of action. Most, if not all of the synephrine being sold as a dietary supplement is extracted and synthesized from the Citrus aurantium plant, more commonly known as bitter orange. Just like ephedrine, synephrine has vasoconstrictive abilities, although at a lesser potency compared to ephedrine. There is no mention of synephrine in editions of Drill's Pharmacology in Medicine later than the 3rd, nor is there any reference to synephrine in the 2012 Physicians' Desk Reference, nor in the current FDA "Orange Book". One current reference source describes synephrine as a vasoconstrictor that has been given to hypotensive patients, orally or by injection, in doses of 20–100 mg.