Caffeine is metabolized in the liver by the cytochrome P450 oxidase enzyme system, in particular, by the CYP1A2 isozyme, into three dimethyl xanthines, [188] each of which has its own effects on the body:

Normally, adenosine levels build up over the day, making you increasingly more tired and causing you to want to go to sleep. So, how do these gummies compare to other forms of caffeine? In this section, we’ll compare caffeine gummies to caffeine pills, caffeinated beverages and other liquids, and caffeine vaporizers. Gummies and Pills Are Slow-acting and Have Low Bioavailability So how exactly does coffee, and caffeine more generally, make us more energetic, efficient and faster? How could this little molecule possibly supply the human body energy without calories? Could caffeine be the proverbial free lunch, or do we pay a price for the mental and physical energy – the alertness, focus and stamina – that caffeine gives us? Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals. [135] Death from caffeine ingestion appears to be rare, and most commonly caused by an intentional overdose of medications. [144] In 2016, 3702 caffeine-related exposures were reported to Poison Control Centers in the United States, of which 846 required treatment at a medical facility, and 16 had a major outcome; and several caffeine-related deaths are reported in case studies. [144] The LD 50 of caffeine in rats is 192 milligrams per kilogram, the fatal dose in humans is estimated to be 150–200 milligrams per kilogram (2.2lb) of body mass (75–100 cups of coffee for a 70kg (150lb) adult). [145] [146] There are cases where doses as low as 57 milligrams per kilogram have been fatal. [147] A number of fatalities have been caused by overdoses of readily available powdered caffeine supplements, for which the estimated lethal amount is less than a tablespoon. [148] The lethal dose is lower in individuals whose ability to metabolize caffeine is impaired due to genetics or chronic liver disease. [149] A death was reported in 2013 of a man with liver cirrhosis who overdosed on caffeinated mints. [150] [151] Interactions

Caffeine, like other xanthines, also acts as a phosphodiesterase inhibitor. [173] As a competitive nonselective phosphodiesterase inhibitor, [174] caffeine raises intracellular cyclic AMP, activates protein kinase A, inhibits TNF-alpha [175] [176] and leukotriene [177] synthesis, and reduces inflammation and innate immunity. [177] Caffeine also affects the cholinergic system where it is a moderate inhibitor of the enzyme acetylcholinesterase. [178] [179] Pharmacokinetics Caffeine is metabolized in the liver via a single demethylation, resulting in three primary metabolites, paraxanthine (84%), theobromine (12%), and theophylline (4%), depending on which methyl group is removed. Urinary metabolites of caffeine in humans at 48 hours post-dose [180] An English neuroscientist on the faculty at University of California, Berkeley, Walker, author of Why We Sleep, is single-minded in his mission: to alert the world to an invisible public-health crisis, which is that we are not getting nearly enough sleep, the sleep we are getting is of poor quality, and a principal culprit in this crime against body and mind is caffeine. Caffeine itself might not be bad for you, but the sleep it’s stealing from you may have a price. According to Walker, research suggests that insufficient sleep may be a key factor in the development of Alzheimer’s disease, arteriosclerosis, stroke, heart failure, depression, anxiety, suicide and obesity. “The shorter you sleep,” he bluntly concludes, “the shorter your lifespan.” Institute of Medicine (US) Committee on Military Nutrition Research (2001). "2, Pharmacology of Caffeine". Pharmacology of Caffeine. National Academies Press (US). Archived from the original on 28 September 2021 . Retrieved 15 December 2022. Drinking between 3–5 cups of coffee per day or more than 3 cups of tea per day may also reduce the risk of brain diseases such as Alzheimer’s and Parkinson’s by 28–60% ( 10, 11, 12, 13). One cup (240 mL) of decaf coffee contains 1–50 mg of caffeine, depending on the brand and serving size. That’s less than half the amount of caffeine in a regular cup.

Trimethyluric acid is a minor caffeine metabolite. [8] 7-Methylxanthine is also a metabolite of caffeine. [189] [190] Each of the above metabolites is further metabolized and then excreted in the urine. Caffeine can accumulate in individuals with severe liver disease, increasing its half-life. [191] Paraxanthine (84%): Increases lipolysis, leading to elevated glycerol and free fatty acid levels in blood plasma. Caffeine Gummies are the tastiest way to boost your day and get you in the zone, with added Pantothenic Acid to help with mental performance and the reduction of tiredness and fatigue 1—and you can now enjoy on-the-go in this delicious Blue Raspberry flavour.From there, it travels to the liver and is broken down into compounds that can affect the function of various organs. Theophylline (4%): Relaxes smooth muscles of the bronchi, and is used to treat asthma. The therapeutic dose of theophylline, however, is many times greater than the levels attained from caffeine metabolism. [46] In fact, evidence shows a 16–18% lower risk of heart disease in men and women who drink between 1–4 cups of coffee daily (providing approximately 100–400 mg of caffeine) ( 29). This causes a relative increase in other signaling molecules, such as dopamine and norepinephrine ( 5, 6). Some beverages combine alcohol with caffeine to create a caffeinated alcoholic drink. The stimulant effects of caffeine may mask the depressant effects of alcohol, potentially reducing the user's awareness of their level of intoxication. Such beverages have been the subject of bans due to safety concerns. In particular, the United States Food and Drug Administration has classified caffeine added to malt liquor beverages as an "unsafe food additive". [246]