Fasting has been part of human life for thousands of years. From religious observance to metabolic health protocols, the reasons people fast are as varied as the methods themselves. But one question comes up across all of them: will my supplements break my fast?
The short answer: most won't. The exception is anything protein-based, like collagen. Ageless NMN, TMG, Essentials Plus, and Genius Sleep are all fast-safe. Vital Beauty Collagen isn't, and here's why. The answer depends on the type of fast you're doing, and which supplement you're taking. Here's what you need to know.
The different types of fasting
Before getting into supplements, it helps to understand what kind of fast you're working with, because the rules differ.
Intermittent fasting is the most common modern approach. It involves cycling between eating and fasting windows, the most popular being 16:8 (16 hours fasted, 8-hour eating window) or 5:2 (two low-calorie days per week). The goal is metabolic: giving your body time without food to tap into stored energy, burn stored energy, and support cellular repair processes like autophagy.
Extended fasting goes beyond 24 hours, sometimes 48, 72 hours or longer. These are less common and typically done for more targeted health reasons. The stricter the fast, the more important it becomes to understand exactly what you're putting in your body.
Religious fasting covers a wide range of practices. Ramadan involves fasting from dawn to sunset, with eating permitted outside those hours, so supplements taken at suhoor (pre-dawn) or iftar (sunset) are fine. Jewish fasting observances like Yom Kippur typically prohibit all food and drink, including supplements. Christian practices vary widely: some traditions like Catholic fasting restrict food intake rather than prohibit it entirely. Eastern Orthodox fasting often restricts animal products rather than food altogether. Greek Orthodox Christians, for example, may abstain from meat, dairy, and fish on certain days, which has implications for collagen specifically (more on that below).
Therapeutic and clinical fasting is done under medical supervision, often as part of managing specific health conditions. If you're in this category, follow your practitioner's guidance over anything else.
What actually breaks a fast
To understand which supplements are safe, you need to know what a fast is actually sensitive to.
From a metabolic standpoint, a fast is broken when you trigger digestion. The main culprits are calories, particularly from protein and carbohydrates. Protein stimulates digestion and can trigger an insulin response even in the absence of carbohydrates.
Sugars and carbohydrates tend to shift your body out of a fasted state more directly, while fat has a much smaller effect, which is why black coffee with a small amount of MCT oil sits in a grey area for many fasting practitioners.
From a religious standpoint, the rules are set by the tradition itself, not biology. Some traditions permit water and medications but nothing else. Others are more flexible. When in doubt, consult your religious authority - they'll have a clearer answer.
Supplements that won't break your fast
Most supplements are non-caloric and contain no protein or sugar. Capsules, tablets, and unflavoured powders without added sweeteners or fillers generally won't trigger a metabolic response.
In the Simply Nootropics range, the following are considered fast-safe:
Ageless NMN is an NAD+ precursor in powder or capsule form. It contains no protein, no sugar, and no meaningful caloric content. NMN is taken for cellular energy and anti-ageing support, both things that remain relevant whether you're fasting or not.
Genius Sleep, Essentials Plus, TMG (both the powder and the capsules) don’t contain ingredients that are caloric in any meaningful sense. Taking them at any point during your intermittent fast is perfectly fine.
The one exception: collagen
Collagen is protein. That is the entire point of it: bovine collagen peptides that your body uses to support skin elasticity, joint health, and connective tissue. Because it's a protein source, taking collagen during a fasting window will break your fast from a metabolic standpoint.
This applies to Simply Nootropics Vital Beauty Collagen in all three flavours, Unflavoured, Mixed Berry, and Mango Passion. It also applies to collagen from any other brand. Protein is protein.
The good news is that collagen doesn't need to be taken fasted to be effective. It's best absorbed alongside food, and pairing it with a vitamin C source further supports uptake. Shifting it into your eating window is easy and costs you nothing in terms of results.
Essentials Plus and fasting: a natural pairing
Essentials Plus is worth calling out specifically, because it's the supplement that pairs most naturally with a fasting lifestyle, and addresses the side effects that make fasting feel harder than it needs to.
The formula combines eight ingredients: Ashwagandha, Rhodiola Rosea, Panax Ginseng, Brahmi, and four others, all targeting stress resilience, cognitive performance, and sustained energy. These are precisely the things that take a hit during fasting windows, particularly in the early stages when your body is adapting.
Ashwagandha helps regulate cortisol, which tends to rise during fasting periods. For people who find that fasting makes them feel wired, anxious, or irritable - elevated cortisol is often the reason. Rhodiola Rosea supports mental stamina and reduces the perception of fatigue, which is useful when brain fog is your main complaint mid-fast. Panax Ginseng has been studied for its role in cognitive function and physical endurance. Brahmi has a long history of use in Ayurvedic medicine for memory and focus.
None of these ingredients are caloric. None will trigger digestion. And all of them target the friction points that make fasting unsustainable for a lot of people, not the idea of fasting, but the 11am brain fog, the stress reactivity, the low-grade fatigue that makes it hard to get through a morning meeting.
Taking Essentials Plus in a fasting window is not only safe, it's arguably the best time to take it.
