Leslie's Corner: The Lowdown on Supplement Fillers and Flow Agents

Do you really know what’s in your supplements? 

I’ve been taking supplements since I was diagnosed with autoimmune issues in 2004. I remember going to Vitamin Cottage, my local health food store in Boulder, Colorado, and being grateful to just find the laundry list of supplements prescribed by my health care practitioner among the many shelves of supplements.

I probably started with 15 different supplements, all prescribed to me based on deficiencies detected in my blood and urine.

Once I had the bottles, I simply took the supplements. No label reading. Just pill popping. Job done.

But once I began to look into the supplement industry, I realized that not all supplements are created equal. Many brands contain what are known to supplement manufacturers as supplement fillers and flow agents.

What are Supplement Fillers?

Supplement fillers are there to ‘bulk out’ the supplement capsule you are taking. They can range from talc and magnesium stearate to titanium dioxide and propylene glycol.

As a matter of fact, when I first spoke with encapsulators about manufacturing our spermidine supplement Primeadine®, I was told that I would need to add talc to make the food-grade, raw material ‘heavier’ so it would more easily ‘fit’ into two capsules – easier for the consumer.

However, I’m half Taiwanese and I lost an aunt and an uncle to stomach cancer, and I was aware of research out of Taiwan published in 2019 showing the link between non-asbestos oral talc and stomach cancer.

Because I myself have already lived 8 of my 9 lives health-wise, I’m very careful of what I put into my body and talc is definitely not something I want – for me or for you.

As a result, you need to take 3 capsules instead of 1 or 2 to get what we consider a minimum effective dose of spermidine: 1mg per day.

What about Supplement Flow Agents?

Supplement flow agents are ingredients incorporated into the supplement material to make the raw materials ‘flow’ faster through the giant hoppers (imagine a reverse vacuum cleaner pushing powder into the large ‘plates’ that hold dozens of empty supplement capsules). These can include hydrogenated soybean oil or other industrial seed oils – both of which appear to create ‘wobbly’ cell membranes instead of perfectly round, stable membranes. We don't want that either.

As a matter of fact, we actually ‘de-fat’ our wheat germ to avoid the naturally occurring vitamin E in the wheat germ from going rancid and unstable. In addition, we have recently reformulated our product to take out the very small amount of rice husk that was originally used as a flow agent. This means that the yield in each manufacturing batch is lower, but that is very small price to pay to keep our integrity and your trust in us intact.

I put a lot of thought into the purity of our spermidine supplements, making sure that they are food-grade and therefore more bioavailable and recognized by the body, but also so that the other polyamines that naturally occur with spermidine – spermine, which appear to lengthen telomeres, and putrescine, a precursor to the body making both – are included in our formulation.

If I wouldn’t want it in my body, I don’t want it in yours.