Zest is formulated to contain about the same amount of caffeine as a cup of coffee. We are coffee lovers ourselves, and designed it so that it can be both a supplement or a replacement to coffee. If you find yourself wanting a cup of coffee in the morning or afternoon, you can do so without any issues.

When you consume caffeine, the caffeine embarks on a 15 to 20-minute journey through your small intestine, into your bloodstream. This typically means it make take half an hour or more, to feel the effects of a caffeine pill, or a cup of coffee - which is more time you’ll have to spend suffering through symptoms of “sleep inertia” - the morning grogginess you typically feel in the morning when you first wake up. Zest’s proprietary delayed-release capsule gradually releases caffeine and other active ingredients, after an initial 7 hour delay. This allows you to wake up with caffeine already in your bloodstream, counteracting sleep inertia and helping you feel alert and energized from the moment you wake up.

While you’re awake and going about your day, a chemical compound called adenosine gradually accumulates in parts of your brain. Adenosine is typically what makes you feel drowsy and ready for bed. Caffeine works by binding to adenosine receptors in our brain. When caffeine binds to those receptors, it blocks our ability to feel the effects of adenosine, so we feel less sleepy, more energetic and focused. Because adenosine is cleared from your brain when you sleep, this frees up the receptors such that caffeine is able to more effectively bind to them. This effectively means that you’ll be able to better feel the effects of caffeine, and feel more alert and focused as a result.

For the average person, the recommended amount of sleep time is around 7-9 hours. We’ve carefully designed our pill to best suit everyone’s sleep needs, such that you’ll only wake up after 7-8 hours. We recommend consistently taking the capsule for a few weeks, which will help your body naturally regulate a consistent sleep schedule and wake-up time.

Typically, when you wake up during the later part of a sleep cycle, you may experience grogginess, as you are in REM sleep, or deep sleep, also known as NREM stage 3 and stage 4. This is often why short 20 minute naps are recommended over longer naps, unless you can sleep for a full 90-minute sleep cycle. We’ve designed our capsule to release caffeine towards the end of your sleep cycle, and timed it such that you’re less likely to be in these stages when the caffeine activates. Additionally, once released, caffeine helps ensure that you wake up naturally from a lighter sleep stage and thus, mitigating the effects of sleep inertia from waking up suddenly from a deeper sleep stage.

If you need more than 8 hours of sleep, you can always opt to not take the timed-release capsule. Additionally, if your body is sleep-deprived, your accumulated sleep debt, and your corresponding “sleep drive” or “sleep pressure” may outweigh the caffeine’s effects. This means you may not wake up from the caffeine.

Our product stands out in several key ways: 1. Advanced Release Mechanism: Our delayed-release coating is highly advanced, developed in collaboration with pharmaceutical scientists and neuroscientists. Unlike other products, which may release caffeine prematurely, our formulation is designed to reliably release caffeine after 7–8 hours of sleep, ensuring you wake up feeling refreshed and alert. This has been clinically validated — read our published peer-reviewed study here. 2. True Delayed-Release, Not Just Extended/Sustained-Release: Many products labeled as “extended-release” or “sustained-release” gradually release caffeine over time, starting shortly after ingestion. In contrast, Zest is a true delayed-release system that holds off releasing caffeine for a full 7 hours, perfectly timed to coincide with waking up, sustained over the course of 2+ hours. This ensures the caffeine works exactly when you need it, without interfering with your sleep, and without causing a crash. 3. Scientifically Backed and Validated: We’ve invested heavily in the development and testing of our release technology to ensure robustness and reliability. Our formula has been rigorously tested to provide consistent results, so you don’t wake up too early or experience uneven effects. 4. Premium Ingredients: We source the highest quality ingredients from trusted European suppliers in countries like Switzerland and Germany. This ensures both effectiveness and safety for our users. While our product is priced higher than some alternatives, we believe it delivers unparalleled quality and performance. If you’re looking for a reliable, science-backed solution, we believe Zest to be the best option available. Learn more about our science and our background here.

This product is not intended to treat, cure, or prevent clinical sleep disorders. The following section is for educational and information purposes only, does not constitute providing medical advice. Always consult your physician or clinician before using this product. The gold standard treatment for insomnia is CBT-i. The first line of treatment technique in CBT-i is often “sleep restriction therapy”, which involves restricting the amount of time you spend in bed. Zest can help support waking up at a set time every day, and help you better anchor your wake-up times to be more consistent. In this particular case, taking a caffeine-based product such as Zest can be beneficial for managing symptoms of insomnia and aligning your circadian rhythms.

Don’t worry - this recently trending advice from Dr. Huberman is not strongly supported by science. One of the biggest claims behind delaying caffeine is that it prevents interfering with the body’s natural cortisol rhythm. But this argument is misleading. The idea that delaying caffeine prevents "extending" the cortisol peak is also flawed. Caffeine will still cause a rise in cortisol even if you delay intake, meaning the timing doesn’t make much difference compared to the amount. If avoiding cortisol spikes were truly a concern, then morning workouts should also be discouraged—yet research overwhelmingly supports early exercise for energy and metabolism. To mitigate an afternoon crash, our timed-release capsule gradually releases caffeine, and maintains a more gradual and consistent level of caffeine in your bloodstream, avoiding any large spikes and subsequent crashes. This steady release helps sustain your energy levels throughout the day and avoid any afternoon crashes from caffeine. Read more here.