Why Do My Supplements Smell Bad?

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The Pure TheraPro Team

The Pure TheraPro Education Team is comprised of researchers from diverse backgrounds including nutrition, functional medicine, fitness, supplement formulation & food science. All articles have been reviewed for content, accuracy, and compliance by a holistic integrative nutritionist certified by an accredited institution.
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Has this ever happened to you--You open your new bottle of supplements and you can’t get over that smell. It’s musky, earthy, sulfur-like, whatever it might smell like—it’s not good! So, does this mean your vitamins are spoiled? Is there something wrong with them?

Quite the contrary. If you purchased products that are free from excipients, flow agents, fillers, artificial flavors or colors and any other junk, your supplements will likely not smell too great. They will smell natural, and by natural, I mean that they might smell bad to you—and this is perfectly normal.

When supplements contain additives, they mask the natural ingredients’ way of naturally behaving. These coatings, processes, dilutions, artificial additives conceal the smell, taste and color, but there is a price. The over-processing, fillers, flow agents and other garbage affects the supplements’ absorption rate and may even be a potential allergen to those who are sensitive to these ingredients. Over time, they can even contribute to gut inflammation and other issues.

Vitamins might be coated to give tablets a certain color, flavor or make them easier to swallow by adding an artificial “gliding” agent. Fillers might mask unpleasant odors and tastes or be dyed a certain color to conceal  inconsistencies from batch to batch. Flow agents such as magnesium stearate might be added to help the raw materials run more efficiently through the manufacturing process.

This is the price one pays for supplements that are not pure. So, the question becomes—do you want supplements that look and smell pretty but might include chemicals that are harmful to your health? Or is it more important to better understand that pure, natural supplements might not always look pretty, smell wonderful and be cookie-cutter replications from bottle to bottle? Hopefully, you picked pure over pretty! Aside from that earthy, natural smell of your excipient-free supplements, here’s what else you can expect:

The Color: Variances may occur from lot to lot. You may notice that the capsules in one bottle you purchase are pale yellow, for example, and the next bottle you purchase a few months down the road are dark yellow. Does this mean they are bad? Did the formulation change? No, that’s not it.

Just as in nature, no flower is exactly identical to another, color variances may be noticeable from batch to batch simply due to the raw materials. The difference in color, however, does not at all affect the potency of the product.


Had the product included additives such as rice flour or cornstarch, you wouldn’t notice this variance. The ingredients could also be dyed in the manufacturing process, contaminating the raw materials with chemicals. Remember that the appearance of the product is not your greatest concern—its potency and bioavailability is.

Chemical Reactions: In nature, two elements may come together and cause a reaction under particular climate or temperature conditions, which may lead to a change in appearance to that substance. When some of the minerals and raw materials in the capsule are exposed to air and humidity, a color change may occur. Copper (as the chelate), for example, reacts with iodine (as potassium iodide), which can result in brown specks in a supplement. This reaction is common with the combination of exposure to air and humid conditions but does not affect the potency of the product. This is more common when natural, filler-free supplements are exposed to heat, moisture and humidity. Keeping capsules in the original container with the natural desiccant can prevent this from occurring.

Storing Your Supplements: Supplements that are free of fillers, excipients, flow agents and heavy preservatives should be stored in a cool, dry place away from direct sunlight. Some vitamins degrade when exposed to sunlight, such as vitamin K2. Others are highly hygroscopic (B vitamins, for example) and need to be stored in a dry place. Some might keep their optimal freshness if refrigerated. Be sure to read the label for specific instructions regarding how to best store your vitamins.

Keep in mind that without heavy preservatives, an opened bottle may degrade prior to the expiration date listed on the bottle. Only open a bottle of supplements if you plan to take them on a continuous basis and finish that bottle. If you know that you are going to stop and start and stop and start taking a certain supplement, it is best to store that bottle in the refrigerator for optimal freshness.

Sourcing: It’s in your best interest to always investigate the sourcing of the raw materials in your supplement. Are the raw materials non GMO? Are they sourced from China? Are the raw materials third-party tested? As of July 2011, over 60% of dietary supplement ingredients sold in the United States were imported from China. Raw materials from China are less expensive, and many companies look for ways to cut corners and increase their profit margin.The key to an excellent nutritional supplement, however, is its raw materials and quality control.

If the company cannot tell you where their raw materials are sourced, or if they have shared with you that the raw materials are from China, it is best to move on and find a company that believes in higher standards and quality

Quality Assurance:

Third party testing is one of the most important elements of ensuring that products are safe. Third party testing means testing is performed by an accredited laboratory and ensures that heavy metals, such as lead and mercury, environmental toxins, pesticides, dioxins, PCBs and microbial contaminants are not in your supplements.

Be sure the company is investing in this testing to provide clean and reliable supplements. Third party testing also verifies that the supplements comply with the mandates of all relevant regulatory agencies.

Patented ingredients also pack a punch since they are backed by clinical studies to support the supplement’s safety and efficacy. Branded ingredients usually go through a much higher quality standard of manufacturing and come with evidence-based literature to support their health claims.


At Pure TheraPro Rx, we create supplements that build a healthy body, and we do this by first building your trust.

We will never purchase raw materials because of cost, and risk potential health hazards. For this reason, our entire product line is China-free---and we intend to keep it that way! We believe raw materials from China may pose a potential health risk, based on a long history of recalls and occurrences, such as historically China-made products containing heavy metals and other cancer-causing contaminants. We have the word “Pure” in our name for a reason.

We choose our raw materials based on quality, not cost. Although they may be more expensive, we believe in going the extra mile to provide quality and peace of mind for our customers. You will never find fillers, flow agents, excipients, heavy preservatives and other chemical ingredients in our product line. We believe in providing our customers with the purest supplements possible.

Increased cost to us does not mean increased cost to you! Being that we are direct-to-consumer with no middle man raising our expenditure, we are able to provide the highest quality, pharmaceutical grade supplements at affordable prices to our customers—not just to the wealthy—but everyone!

We use a GMP certified and FDA inspected manufacturing facility along with rigorous quality standards to produce our line of exceptional pharmaceutical-grade nutraceuticals. Our health-practitioner-recommended formulations are typically patented and comprised of highly researched ingredients for maximum efficacy. All Pure TheraPro Rx brand supplements are non-GMO, China-free, made in the USA and free of excipients, fillers and flow agents that hinder bioavailability.

Purity is Priority.