Together With Momentous
Open your bathroom cabinet. Count the supplement bottles. How many do you see?
According to CDC data, more than half of American adults take at least one supplement. And the older you get, the more likely you are to take four or more every single day. And roughly 40% of supplement users have been at it for more than five years. That's not casual experimentation. That's a committed daily habit for tens of millions of people.
We’re not anti-supplement. You’ve seen us break down countless studies about supplements, ranging from the good to the bad and the ugly.
But here’s the part that bothers us: most of the supplements people take are picked up based on a great story, not because we have evidence that show they work.
I'm not judging. I've been that person. Early in my career, my shelf looked like a small pharmacy. BCAAs, glutamine, a greens powder that tasted like lawn clippings mixed with regret, and a pre-workout booster I'd rather not name (rhymes with “hacked CD”). I took all for different reasons.
At some point, I assumed more was better; then I assumed I knew who to trust; and finally, because the fitness industry I worked in treated supplementation as a prerequisite for being serious.
It took years of reading research, working with clients, and being honest with myself to reach an uncomfortable conclusion: most of it amounted to doing nothing. Less was more. And determining what the body needs matters more than what someone is selling.
The more I learned, the more I realized people just needed more clarity about what to expect, rather than the endless push of marketing and hype. It was a big reason we decided to create APC in the first place. Report the data, interpret what makes a difference, and leave the rest up to you.
The real issue isn't the supplements. It's what results they will realistically deliver.
Let’s Talk About Foundational Health
The global supplement industry reached $177 billion in 2023 and continues to grow at approximately 9% per year. That kind of money is built on a specific emotional transaction. You feel the gap between where you are and where you want to be, and a product promises to close it. That pitch works because the underlying desire is legitimate.
You want to feel better. You want more energy. You want to protect your health as you get older. But the things that actually close that gap aren't in bottles. They never have been.
If I wanted to give a recipe to everyone to build timeless foundational health and has enough research to convince even the greatest skeptic, it would look like this:
Enjoy protein at every meal. You can choose the source. Total protein matters more than source or timing.
Include fiber-based foods multiple times per day. You need more fiber. The data is screaming at us all, and we keep ignoring it.
Eat more whole foods and fewer ultra-processed foods. The more ultra-processed you eat, the more you eat. And the more likely you are to struggle with your diet…
But, there’s no need to be neurotic about every treat you enjoy. A healthy diet doesn’t need to have zero ultra-processed foods. There’s a time and place for it, and they can help you stay consistent with the healthier options.
Take a daily walk — indoors or outside. In fact, make time to take two or three. They don’t have to be long.
But if it’s indoors, make sure you get outside at some point. Fresh air and the sun are good for you.
Resistance train at least three times per week. Don’t just show up. Chase the hard reps, whether using light or heavy weights. Pick exercises you can do, and remember that tension is what you’re chasing. 10 reps are not 10 reps unless the last 2-3 are a legitimate challenge.
Read a book, do a puzzle, or find anything that forces you to be curious or learn.
Take a deep breath, or do something help you calm down. You can’t control whether you get stressed. But you can influence how much stress controls you.
Sleep seven to eight hours. Yes, it can be hard. But sleep changes everything.
Be around people who make you laugh. If not in person, call them. Fill you days with joy.
Do kind things for others. Be selfless. Or just let people know they make a difference. It will benefit you and them.
Take time to recover: mentally, physically, and emotionally. “No days off” only looks good on posters.
If you’ll notice, the majority of the list doesn’t cost much, or anything at all. And these are the foundations of health, longevity, happiness, and meaning.
Are there products that can help you get there? Of course. Research suggests 95 percent of people don’t get enough fiber. I’ll be the first person to tell you to eat more oats, legumes, spinach, raspberries, and avocado.
Because people are still deficient, we invested two years researching the best possible fiber product so you can improve your gut health the right way and make it easier to get enough fiber instead of being vulnerable.
But there are only so many products that fill a real deficiency. The list above? That’s the gold standard. Either your habits and behaviors support those goals (or offset where you struggle), or they are likely not the best use of time or money.
Real health is built on foundational behaviors that deliver asymmetric, exponential upside.
I've written versions of that list before, and I'll probably write it again. Because it keeps being true, and it keeps being the thing people skip on their way to the supplement aisle.
The U.S. Preventive Services Task Force reviewed 84 studies to determine whether vitamin and mineral supplements prevent cardiovascular disease and cancer, the two leading causes of death in this country. They recommended against beta-carotene and vitamin E, and found insufficient evidence for almost everything else.
The International Olympic Committee reviewed performance-enhancing supplements and reached the same conclusion. Very few do anything meaningful for the best athletes on the planet, let alone the rest of us.
A 2025 rapid review spanning over 5.5 million participants reinforced the pattern. Multivitamins showed cognitive benefits in older adults (if you’re over 50, a multivitamin is probably a good idea!), but no benefit for all-cause mortality.
Two of the most authoritative bodies in sports performance and preventive health have independently reached the same conclusion. That tells us something.
But it doesn't mean nothing works. It means most things don't. And the few that do are boring, cheap, and well-studied enough that they don't need aggressive marketing to justify themselves.
Three Supplements That Earned Their Place
I want to start here, with what works, because that's more useful (and a lot shorter) than leading with a list of what doesn't.
Protein
It’s easy to think about protein as only for building muscle. But it’s so much more. Protein is the building block of every cell in your body. It’s your enzymes, tissues, and hormones, and the key to form, structure, and function.
You don’t need to max out on protein, but you do need to prioritize it because it is essential.
The most comprehensive meta-analysis on protein supplementation (49 randomized controlled trials, 1,863 participants) found that protein supplementation significantly increases strength, fat-free mass, and muscle fiber size. Benefits plateau at approximately 1.6 to 2.2 grams per kilogram of body weight per day, roughly 0.7 to 1 gram per pound. Going higher doesn't add much. And if you’re not active, as low as 1.2 grams per kilogram could be enough.
A 2024 review of 47 studies found that higher protein intake significantly prevented muscle loss during weight loss. If you've ever dieted and felt like you lost the wrong kind of weight, this is likely why. Protein is the difference between losing fat and losing the muscle you worked to build.
Trained individuals see more benefit than untrained ones. Older adults need to be even more intentional about it because the body becomes less efficient at using protein with age.
Whey protein isolate is the most studied form, but the source matters less than hitting the daily number. If you prefer a plant-based option, that works, too.
If you'd rather get it from whole food options, you don’t need a supplement. But if you’re not getting enough, it's better to add protein powder than to deprive your body of what it needs.
Creatine Monohydrate
I've probably recommended creatine to more people than any other single thing in my career. Not because it's magical, but because the research is so consistent, it almost feels unfair to other supplements.
The largest body-composition meta-analysis on creatine, covering 143 randomized controlled trials, found increases in body mass, fat-free mass, and reductions in body fat percentage.
A 2024 meta-analysis of 23 studies found that creatine plus resistance training increased upper-body and lower-body strength. A 2025 review confirmed these benefits extend well beyond young athletes. Older adults showed significant strength gains too, making creatine one of the most evidence-backed tools for aging well.
Over the past 5 years, cognitive benefits have become more evident. Creatine helps when you’re stressed and when you’re not getting enough sleep. It supports brain health as you get older. It fills nutrient gaps if you’re vegan or vegetarian. It can support the battle against depression, and might even help protect against neurodegeneration.
None of these things happens alone. And creatine does not do all the heavy lifting. But it does help, and the safety profile is incredible.
Five grams a day if you want muscle or strength. Anywhere from 10 to 20 grams per day for cognitive protection. Stick to creatine monohydrate because that’s where the research leads. No fancy forms needed (HCl, buffered, and other variations haven't proven any advantage over plain monohydrate). If anything in the supplement world qualifies as backed by evidence, this is it.
Vitamin D
This one requires honesty. If your vitamin D levels are already sufficient (above 30 ng/mL), supplementation probably won't change much for you. A 2023 review in the Journal of Bone and Mineral Research found that in vitamin D-replete adults, supplementation didn't decrease bone loss, fractures, falls, cancer incidence, or cardiovascular risk.
However, an estimated 35-50% of the global population has suboptimal Vitamin D levels. That number climbs higher if you live in northern latitudes, have darker skin, are over 60, or spend most of your day indoors. For that massive group, supplementation addresses a real biological gap.
Correcting a Vitamin D deficiency has meaningful effects. Accumulating evidence suggests reduced cancer mortality, better immune function (particularly for upper respiratory infections), and lower all-cause mortality.
The recommendation is straightforward: get tested. If your level is below 30 ng/mL, supplement with 1,000 to 3,000 IU daily. Or prioritize sunlight and fatty fish.
The Supplements You Can Probably Stop Buying
Now for the harder conversation. If you recognize something you're currently taking on this list, that's not a reason to feel foolish. The marketing for these products is sophisticated, and in many cases, the underlying science appears plausible. The gap isn't between smart people and dumb people. It's between what lab research suggests might work and what controlled human trials actually show.
I'd group these by why they fail.
You already get them from food
BCAAs (leucine, isoleucine, and valine) have been marketed for years as essential for muscle growth and recovery. A systematic review of 12 randomized controlled trials found no significant improvements in body composition, performance, or strength at an average dose of 19.5g per day. The reason is straightforward: if you're eating adequate protein, you're already consuming plenty of BCAAs. They're in the protein. Supplementing on top of that is redundant.
Glutamine follows the same pattern. It's been a gym staple for decades, but your gut and liver absorb most oral glutamine before it ever reaches muscle tissue. So if you’re taking it for performance, multiple human trials have failed to show muscle-building benefits in healthy adults. Glutamine has real clinical applications (burn recovery, sepsis, prolonged endurance events), but for general fitness purposes, the research isn't there.
If you're eating protein at most meals, you've already covered what both of these claim to provide.
The promises don't match the biology
Testosterone boosters (D-aspartic acid, tribulus terrestris, fenugreek, and their rotating cast of ingredients) promise increased testosterone, more muscle, and improved libido. Multiple randomized controlled trials in resistance-trained men show null or negative effects on testosterone levels. No meaningful improvements in any training outcome.
If your testosterone is genuinely low, that's a medical conversation worth having with your doctor. What does support healthy testosterone within normal ranges? Sleep, strength training, maintaining a reasonable body fat percentage, and managing chronic stress. All free. All proven. All things you can start this week.
Fat burners occupy similar territory. The market exceeds $28 billion, which is striking given that the primary active ingredient is usually just caffeine with a label redesign. A meta-analysis of CLA (conjugated linoleic acid) found effects that were small, inconsistent, and clinically insignificant. The mechanism for fat loss hasn't changed and won't: a sustained caloric deficit, supported by adequate protein and resistance training to protect muscle mass. No pill shortcuts that process.
The biomarker moves, but nothing else does
This category is the trickiest because the science sounds right.
Glucosamine and chondroitin are commonly used for joint pain. But the landmark GAIT trial in the New England Journal of Medicine found no significant benefit over placebo for most participants, and subsequent meta-analyses have been mixed to negative. If joint pain is limiting you, the best evidence points to strength training around the affected joint and working with a physical therapist who can address the mechanical issue rather than masking the symptom.
Greens powders promise the nutritional equivalent of several servings of vegetables in a single scoop. But that’s more storytelling than reality. They lack the fiber, the full phytochemical spectrum, and the satiety that whole fruits and vegetables provide. Evidence for health benefits is limited to small studies with modest results. If eating enough vegetables is the challenge (and for most people, it is), the better investment is to find two or three you actually enjoy and make them convenient. Buy them pre-cut. Roast a big batch on Sunday. Keep frozen options stocked. That's a sustainable system.
And if we’re being honest, the list of “what not to take” can feel almost endless. So we’re just focusing on some of the more popular products.
What This Actually Means for You (And How Arnold Thinks About Supplements)
If you've read this far and you're mentally tallying what you've spent on supplements that didn't deliver, I want to be straight about something: that money wasn't wasted because you made a bad decision. It was wasted because the information available to you wasn't honest. And it’s possible that it wasn’t a bad decision at all.
Some habits we create— whether supplements or otherwise—provide the cue or scaffolding for supportive behaviors that matter.
Remember, anything that supports the foundation is helping you move in the right direction.
If your greens powder helped you eat better the rest of the day, then you can keep doing it if that’s part of the routine that keeps you performing and feeling your best. Or if you tried something and it worked for you, even if the research didn’t back it up, why stop?
There’s tremendous value in personalizing your health journey and building a routine that delivers the outcomes you want. No one — including us — should stop you from doing what has led to great results.
This is about knowing what is most likely to work, and understanding that if you’re not seeing the changes you want, there are steps you can take to save you time and frustration.
Now you have better information. And the good news is that it makes this simpler, not more complicated.
The foundation (how you eat, move, sleep, and connect with people) does most of the work. It always has.
Protein, creatine, vitamin D, and fiber have earned their place through decades of research across millions of participants. Everything else depends on how much they support where you are deficient; they are often optional and sometimes a distraction.
That's not a restrictive conclusion. It's a freeing one. Fewer bottles in the cabinet. Less money spent each month. Less daily decision-making about what to take and when. And more energy directed toward the stuff that actually moves the needle.
When we built Arnold's Stack with Momentous, this was the entire starting point. Not "what can we sell?" but "if someone was only going to take things for the rest of their life, what should they be?"
That’s Arnold’s approach to everything. It’s not about what trends; it’s about what is trend-proof. There’s a value to hard work, consistency, intensity, and not overthinking what you need. Keeping it simple so you can focus on what works.
Grass-fed whey protein isolate with ProHydrolase for digestion. Creapure creatine monohydrate, pharmaceutical-grade, zero fillers. Vitamin D3 at the levels that can help you establish a good level. All NSF Certified for Sport, every batch third-party tested, so that you can know what’s on the label is in the product, and that there’s nothing else you need to worry about.
There’s a value to that calculated approach. Not because supplements are the answer. Because the right ones, specifically, reinforce a foundation that's already doing the heavy lifting, and ensure you’re giving your body what it really needs.
The basics work. They've always worked. And trusting them might be the most underrated health decision you make this year.
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Publisher: Arnold Schwarzenegger
Editors-in-chief: Adam Bornstein and Daniel Ketchell
