Does NOW Vitamins Have Fillers? The Truth About Their Ingredients

January 3, 2026 •

3 min read

According to an article from the National Institutes of Health, all dietary supplement labels are required to list active and other ingredients, such as fillers. While NOW Foods does use functional excipients for manufacturing, the company maintains a strict list of undesirable ingredients and is transparent about what is included in their formulas.

Quick Summary

NOW Foods acknowledges the necessary use of functional excipients in its supplements, but states they do not use common mass-market fillers.

Key Points

Functional Excipients: NOW Foods uses necessary, functional excipients (not fillers) like cellulose and silica for manufacturing.
Mass-Market Fillers Avoided: The company actively avoids common low-quality mass-market fillers such as hydrogenated oil and talc.
Ingredient Transparency: NOW is transparent, listing all 'other ingredients' on its product labels for consumer review.
Magnesium Stearate Phase-Out: The brand has been phasing out magnesium stearate in response to consumer preference, using vegetable-sourced stearic acid instead.
Rigorous Quality Control: NOW supplements undergo extensive in-house and some third-party testing to ensure quality, potency, and purity.
Clean Label Philosophy: The company focuses on using natural, non-GMO, and vegan-friendly excipients for a cleaner final product.

What Are Fillers and Why Are They Used?

In the supplement industry, the term 'filler' can be misleading. A more accurate term is 'excipient,' which refers to any substance in a supplement formulation that is not the primary active ingredient. These are used for several legitimate manufacturing purposes:

Bulking agents: Many vitamins and minerals are needed in extremely small quantities (micrograms), and a bulking agent is required to make the tablet or capsule a manageable size.
Binders: Without binders, a tablet would simply crumble. Binders hold the active ingredients together in a stable form.
Flow agents: These prevent ingredients from sticking to manufacturing equipment, ensuring smooth production and consistent dosing.
Disintegrants: This type of excipient helps the tablet or capsule break apart in the digestive system so the body can absorb the active ingredients effectively.

While excipients are necessary, the type and quality vary significantly between brands. Some companies use cheaper, less desirable ingredients to cut costs, which can include artificial colors, hydrogenated oils, or excessive amounts of certain additives.

NOW Foods' Approach to Excipients and Fillers

NOW Foods openly discusses its use of excipients and takes a strong stance against using many common, mass-market ones. The company is transparent on its website and on product labels about what 'other ingredients' are included.

What NOW Won't Use

NOW Foods has a published list of ingredients it will not use in its supplements. This includes:

Hydrogenated oil
Talc
Crospovidone
Butylated Hydroxytoluene (BHT)

By avoiding these ingredients, NOW ensures its products can maintain a 'natural' claim and align with their overall quality and safety standards.

What NOW Does Use

To manufacture supplements, NOW relies on a selection of carefully chosen excipients. These are described as food-grade or pharmaceutical-grade, vegan-friendly, and non-GMO whenever possible. Common examples include:

Stearic acid (vegetable source): Used as a lubricant and flow agent. NOW has been phasing out magnesium stearate, a similar ingredient, in response to consumer feedback.
Microcrystalline cellulose: A plant-based ingredient that functions as a filler and binder.
Silicon dioxide (silica): An anti-caking agent to prevent clumping and improve product stability.
Vegetarian coating: A protective, plant-based coating for tablets and capsules.
Natural excipients: NOW makes a point of choosing more natural, vegetarian, and vegan-friendly alternatives to mass-market excipients.

Transparency and Quality Control

NOW Foods' commitment to quality extends beyond simply avoiding certain fillers. It includes several practices that benefit consumers looking for a 'cleaner' product.

Key Aspects of NOW's Quality Process:

Ingredient sourcing: The company uses high-quality, sustainably sourced ingredients and chooses organic and non-GMO options when possible.
In-house testing: NOW conducts thorough in-house testing on both raw materials and finished products, performing thousands of tests monthly.
Third-party testing: While most products are tested in-house, some are certified by independent organizations like Informed Sport.
Labeling: NOW provides a full disclosure of all excipients used on every product label, allowing consumers to make an informed choice. For more details, see their official page on excipients: NOW Foods: Functional Ingredients Used in Dietary Supplements.

NOW vs. Mass-Market Supplements: A Comparison

To illustrate the difference in approach, here is a comparison of NOW's ingredient philosophy versus a typical, cost-focused mass-market brand.


Feature	NOW Foods	Typical Mass-Market Brand
Excipient Philosophy	Minimized use of necessary, natural excipients. Avoids common synthetic options.	May use a wide range of excipients, including cheaper or synthetic options, to optimize manufacturing efficiency.
Sourcing	Prioritizes high-quality, non-GMO, and sustainably sourced ingredients.	Less emphasis on sourcing quality; may use lower-grade ingredients.
Testing	Rigorous in-house testing at multiple stages. Select third-party certifications.	May rely on standard industry testing with less oversight, or limited third-party verification.
Transparency	Complete disclosure of 'other ingredients' on labels.	May use ambiguous terms like 'proprietary blend' or have less clear labeling about excipients.
Ingredient Examples	Microcrystalline cellulose, vegetable stearic acid, silica.	Talc, hydrogenated oil, artificial colors, soy lecithin.

Conclusion: Responsible Use, Not Absence

So, does NOW vitamins have fillers? The answer is nuanced: yes, they use excipients, but they are not the same kind of low-quality, mass-market fillers many people seek to avoid. Excipients are a necessary part of supplement manufacturing to ensure the product is stable, properly dosed, and functional. NOW Foods differentiates itself by prioritizing natural, high-quality, and vegan-friendly excipients, minimizing their use, and maintaining full transparency on their labels. By focusing on a 'cleaner' formula and rigorous quality control, NOW offers a high-quality product for those who are concerned about unnecessary additives.

Frequently Asked Questions

Excipient is the technical term for non-active ingredients necessary for manufacturing, stability, and absorption. 'Filler' often carries a negative connotation, referring to cheap or unnecessary additives, though the terms are sometimes used interchangeably.

Excipients serve several critical roles: they bulk up tiny amounts of active ingredients, bind tablets together, ensure smooth manufacturing, and help tablets disintegrate for proper absorption.

NOW has been phasing out the use of magnesium stearate, a common flow agent, in tablets and two-piece capsules due to consumer preference. They primarily use vegetable-sourced stearic acid instead.

Yes. NOW Foods performs thousands of in-house tests on raw materials and finished products every month. Some products also carry third-party certifications from independent organizations.

NOW Foods provides complete transparency. All excipients and 'other ingredients' are fully disclosed on every product label, as required by the FDA.

Cellulose is a plant-derived excipient often used as a binder or bulking agent and is generally considered a neutral, fiber-based ingredient. NOW uses microcrystalline cellulose and hypromellose (cellulose capsule), which are plant-based and suitable for vegetarians.

With over 50 years in the business, a focus on quality and transparency, and extensive in-house testing, NOW Foods is generally considered a reputable brand in the supplement industry.