May 11, 2025

In Defence of the “Nasties”: Why Fillers, Binders & Anti-Caking Agents Aren’t Trying to Kill You

Let’s talk about those so-called nasties in your supplements — fillers, binders, anti-caking agents. You’ve seen the packaging — “No fillers! No junk! No murdery chemicals!” — proudly plastered on the label like it’s some kind of virtue signal. But the truth is, these ingredients aren’t plotting your downfall. They’re not even mildly misbehaving. They’re the unsung workhorses making sure your supplement doesn’t arrive as a sad, clumpy mess or a crumbling catastrophe.

Now, don’t get us wrong — we love a clean, purposeful formula as much as the next health geek. But clean doesn’t mean empty, and science should always outrank scaremongering. Some of these vilified ingredients are there to stop your magnesium turning into cement in the jar. Others help capsules actually fill correctly, so you're not playing nutrient roulette with every dose.

So, let’s get into it. We’re unpacking what these ingredients actually do, when they’re helpful, when they’re just lazy BS, and how to spot the difference between smart formulation and hollow marketing noise. If an ingredient shows up at 0.3% of the formula and makes the whole thing work better — it’s probably not the nutritional antichrist.

The “No Fillers” Hysteria: Clean, but Not Always Clever

The “no fillers” trend has gone full tilt in recent years — and on the surface, sure, it sounds perfect. Who wouldn’t want a squeaky-clean supplement? But peel back the packaging and it’s often less about health and more about hype. In a crowded market, “free from fillers” is just another attempt to shout “we’re better!” — even when the science says otherwise.

What those tidy little labels rarely tell you is that ditching every excipient can actually make products harder to manufacture, less stable, and sometimes completely crap. These ingredients aren’t there to pad things out like a cheap kebab at 2 o’clock in the morning. They help keep capsules consistent, powders free-flowing, and tablets intact longer than a week.

So yes, we’re into smart, stripped-back formulas — but blanket demonising these ingredients? That’s just bad science dressed up in clean-eating drag.

Sure, if your supplement only contains one ingredient, skipping excipients might make sense. But once you’re blending multiple actives, the right excipients can be the difference between a clean formula and a dysfunctional mess.

No, Magnesium Stearate Is Not a Tool of the Illuminati

Let’s set the record straight. Magnesium stearate and silicon dioxide have become the bogeymen of the supplement world — accused of everything short of launching a coup. In reality? They're glorified facilitators.

Magnesium stearate helps powders glide through machinery so your capsules aren’t full of air and guesswork. Silicon dioxide prevents powders from turning into sad little clumps that won’t mix or swallow. They're both used in minuscule amounts (we're talking fractions of a percent), and have been studied, regulated, and safely used for decades.

Unless you're allergic to logic, there’s no reason to fear them. For instance, the European Food Safety Authority (EFSA) has assessed magnesium stearate and found it to be safe at levels commonly used in food and supplements.

The Supporting Cast: Common Excipients & What They Actually Do

Let’s shine a light on the overlooked oddballs doing some of the heavy lifting. These are the most common inactive ingredients found in supplements — and no, they’re not quietly assassinating your liver. They’re just keeping your capsules from becoming chaos.

  • Magnesium Stearate – Flow agent. Used in tiny amounts to keep powders moving through machinery and fill capsules evenly. Claims it “blocks nutrient absorption” have been thoroughly debunked. You’d need to consume industrial quantities to feel anything dodgy. It’s the magnesium salt of stearic acid — a fatty acid found in foods like chocolate and spinach.
  • Vegetable Stearic Acid – Another flow aid. Similar to magnesium stearate but without the magnesium bit. Derived from plants and often used to help form tablets or maintain capsule integrity. Completely inert and digestible.
  • Silicon Dioxide – Anti-caking hero. Keeps powders from clumping into unusable boulders. Naturally found in oats, leafy greens, and even mineral water. Safe, regulated, and present in your diet already.
  • Organic Silica Concentrate – A natural source of silica, used to support powder flow and reduce moisture-related clumping. Still silica, just from a “clean label”-friendly source.
  • Microcrystalline Cellulose – A refined plant fibre used as a binder or filler. Chemically inert and basically a purified version of the fibre you get from veg and fruit. Keeps tablets intact and capsules filled properly.
  • Maltodextrin – A refined carbohydrate used as a carrier for delicate ingredients like herbal extracts. In large quantities, it could spike blood sugar. In the micro-doses used in supplements? Not a drama. Diabetics: keep tabs. Everyone else: no issue.
  • Rice Flour – A clean-label filler or flow agent. Used as a natural alternative to synthetic binders. Minimal functional difference from other excipients, but often preferred for allergen-friendly or “natural” branding.
  • Croscarmellose / Croscarmellose Sodium – A super-useful disintegrant. Basically, it helps your tablet or capsule break down properly in your gut — so the nutrients get absorbed efficiently, rather than passing through like a vitamin-packed pebble. Derived from cellulose and completely safe.
  • Calcium Carbonate – Sometimes used as a filler, sometimes as a calcium source. Found in rocks, yes, but also in leafy greens and dairy. Approved across the EU and UK, it’s safe and inert — though in high doses it can be constipating, which is why it’s used in modest amounts.
  • Hydroxypropyl Methylcellulose (HPMC) – Used in two ways: as a vegetarian capsule shell and occasionally as a binder or coating. Made from cellulose, non-toxic, and widely accepted in food and pharma. HPMC is your friend if you're plant-based or avoiding gelatin.
  • Glazing Agents (Pharmaceutical Glaze / HPMC / Riboflavin) – These help tablets look shiny and uniform, but they’re not just for looks. They provide a protective barrier against moisture and oxidation. Riboflavin (vitamin B2) also adds a natural yellow hue. Think of it as the waterproof jacket of tablet coatings — useful and harmless.

These ingredients typically make up less than 1–2% of a product — and unless you’re knocking back hundreds of capsules a day (which we strongly don’t recommend, obviously), their impact on your body is negligible and their function? Vital.

Myth-Busting: Let’s Calm Down, Shall We?

Because not every long, Latin-sounding ingredient is part of a sinister corporate plot.

  • “Magnesium stearate blocks absorption!”
    No, it doesn’t. It dissolves long before your nutrients do. It’s made from substances naturally found in chocolate and spinach. If you’re fine with a curly kale salad or a Dairy Milk, you’ll survive your supplement.
  • “Silicon dioxide is glass!”
    It’s not. It’s a purified form of silica found naturally in food and water. You’ve been eating it your whole life. You’re still here.
  • “Microcrystalline cellulose is wood pulp!”
    Technically, yes — but it’s refined plant fibre, not a floorboard. It behaves like any other fibre: it passes through, does nothing harmful, and helps your capsule keep its shape.
  • “Maltodextrin is sugar!”
    Also yes — kind of. It’s a carb, and in massive quantities, it could spike blood sugar. In the trace amounts used in supplements? No drama. Just don’t wash your capsules down with a litre of Irn-Bru.
  • “Ewww Gelatin!”
    Only even remotely disgusting if you’ve never eaten jelly, gravy, gummy bears, or chicken wings. And if you have? Congratulations — you’ve already met gelatin. If you’re veggie or vegan, HPMC is your friend.

Wait — Do These Ingredients Actually Help?

Funny you should ask. These unglamorous bits and bobs often play a vital role in making sure your supplement... actually works. They:

  • Help distribute ingredients evenly
  • Prevent clumping and caking
  • Ensure precise capsule fills
  • Extend shelf stability
  • Prevent nutrient degradation during manufacture

While they don’t directly boost absorption, they enable consistency — which helps every capsule dissolve as it should, deliver what it promises, and not go rogue halfway through your digestive tract.

They're not filler. They’re function.

The Context Matters: Clean Isn’t Always Better

Of course, not all formulations need these ingredients. Simple, single-ingredient products? Often just fine without them. Our mushroom extract capsules, for example, are stripped-back and squeaky clean. No fillers, nothing unnecessary.

But for more complex formulations — like our ONE Athlete stacks — a touch of the right excipient makes all the difference. You want precise dosing, smooth blending, and shelf-stable reliability? That’s where these behind-the-scenes players shine.

We don’t use them unless they serve a purpose. And when they do, we use them smartly — with zero tolerance for gimmicks, padding, or anything that compromises performance.

Final Thoughts: Don’t Panic, Just Read the Label

Fillers, binders, anti-caking agents — they’ve been painted as the villains of modern supplementation, but in reality, they’re just practical tools used (sparingly) to keep your supplements consistent and effective. Yes, there are brands that overdo it. But not every unpronounceable word is an assault on your wellbeing.

At One Life, we build formulas based on purpose — not fear, hype, or hollow claims. If we can leave it out, we will. If it needs to be there, it’s because it does something useful. And that’s the difference between honest formulation and marketing theatre.

So the next time you spot “magnesium stearate” on a label, don’t freak out. Ask what it’s doing there. Odds are, it’s just helping your supplement actually do its job.

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Written by Chris Simon