“Science-backed” is the most overused phrase in the supplement aisle. Most brands mean they found a study somewhere that mentions an ingredient they happen to use. Shaklee’s claim is more specific and more checkable: the company has funded its own clinical research, published in peer-reviewed journals, on its actual products and customers. This article walks through what that science actually consists of, how to interpret it honestly, and where its limits are. No hand-waving, just what the data shows.
1. The Landmark Study: research on real long-term users
The cornerstone is the Landmark Study, published in the peer-reviewed Nutrition Journal in 2007. The lead investigator was Dr. Gladys Block of the University of California, Berkeley, a nutritional epidemiologist whose food-frequency questionnaires are used in research worldwide.
The design compared three groups of adults: long-term users of multiple Shaklee supplements (averaging roughly 20 years of use), single-multivitamin users, and people taking no supplements. After statistical adjustment for age, sex, income, education, and body mass index, the long-term multiple-supplement group showed more favorable levels of several clinically meaningful biomarkers:
- Lower homocysteine, an amino acid linked, when elevated, to cardiovascular risk.
- Lower C-reactive protein (CRP), a standard marker of systemic inflammation.
- More favorable lipid ratios, including higher HDL and lower triglycerides.
- Lower observed prevalence of high blood pressure and several chronic conditions versus non-users.
The honest caveat: the Landmark Study was cross-sectional. It measured people at one point in time, so it demonstrates a strong association, not proof of cause and effect. People who take supplements consistently for two decades may also exercise more, eat better, or have higher health awareness, “healthy-user bias.” The investigators adjusted for the obvious confounders, but no observational study eliminates all of them. What makes the study remarkable is not that it settles the question, but that it exists at all: very few supplement companies have ever funded independent, peer-reviewed research of this scale on their own long-term customers.
2. Beyond Landmark: targeted clinical and bioavailability research
Shaklee states the product line is supported by 110+ clinical studies and 70+ patents and patents pending. Several published or presented studies on specific Shaklee products examined questions that matter more than marketing slogans:
- Bioavailability, whether nutrients are actually absorbed rather than passed through. A vitamin is only useful if it dissolves and is taken up; disintegration and absorption testing addresses this directly.
- Cardiovascular and antioxidant markers, studies on omega-3 and antioxidant formulas measuring blood levels and oxidative-stress indicators.
- Probiotic viability, whether the organisms in a probiotic survive stomach acid and reach the intestine in useful numbers, which depends heavily on delivery technology.
The general scientific principle worth internalizing: dose on the label is not dose in the bloodstream. Formulation, delivery format, and ingredient form determine how much actually reaches your cells. This is the gap between cheap supplements and well-formulated ones, and it is where third-party and in-house research earns its keep.
3. Quality control: testing that surpasses US Pharmacopeia
Science isn’t only the clinical trials, it’s also the analytical chemistry behind every batch. Shaklee states it performs more than 350 tests on a new ingredient before acceptance, screening for:
- Heavy metals, lead, arsenic, cadmium, and mercury, which can accumulate in botanical and marine ingredients.
- Pesticide and herbicide residues in plant-derived materials.
- Microbial contamination, bacteria, yeast, and mold.
- Identity and potency, confirming the ingredient is what the label says, at the stated strength.
The benchmark term is US Pharmacopeia (USP), the nonprofit that sets purity and quality standards for medicines and supplements in the United States. Crucially, dietary supplements are not legally required to meet USP standards. A company that voluntarily tests to or beyond that bar is choosing a stricter standard than regulation demands, and that choice is verifiable, because rigorous testing generates certificates of analysis that a serious manufacturer will discuss openly.
4. How to read supplement science like a scientist
Whether you’re evaluating Shaklee or any other brand, a few questions separate evidence from marketing:
- Was it peer-reviewed and published, or just an unpublished “study” on a sales page?
- Was it on the actual product, or on a single ingredient at a dose unrelated to what’s in the bottle?
- What was the study design? Randomized controlled trials outrank cohort studies, which outrank cross-sectional snapshots, which outrank testimonials.
- Is bioavailability addressed, or only the amount on the label?
- Who funded it, and is that disclosed? Industry funding doesn’t invalidate research, but transparency matters.
By these standards, Shaklee’s research record, a peer-reviewed flagship study with a respected university, plus published work on specific products and a documented testing program, places it well above the typical supplement brand, while still falling short of pharmaceutical-grade randomized-trial certainty. Both of those things are true at once, and saying so is what makes the science trustworthy.
The bottom line
The science behind Shaklee products is real, published, and unusually transparent for the supplement industry, anchored by the UC Berkeley Landmark Study, supported by targeted clinical and bioavailability research, and backed by ingredient testing that exceeds legal requirements. It is association-grade evidence on the long-term outcomes and analytical-grade evidence on quality, not proof that any single product will produce a specific result for you. Supplements also remain a complement to, never a replacement for, a good diet, sleep, and exercise.
You can read Shaklee’s own summary of the Landmark Study and its research, review its quality commitment, or shop Shaklee USA products through the official store.
Sources Cited:
1. Block G, Jensen CD, Norkus EP, et al. Usage patterns, health, and nutritional status of long-term multiple dietary supplement users: a cross-sectional study. Nutrition Journal. 2007;6:30. doi:10.1186/1475-2891-6-30.
2. United States Pharmacopeia (USP). Dietary Supplements Standards and Verification Program. usp.org.
3. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need to Know. ods.od.nih.gov.
4. U.S. Food & Drug Administration. Current Good Manufacturing Practices (cGMPs) for Dietary Supplements. fda.gov.
5. Shaklee Corporation. Science & the Landmark Study. https://us.shaklee.com/en_US/new/proof-supplements-work.
6. Shaklee Corporation. Highest Quality Commitment. https://us.shaklee.com/en_US/new/highest-quality-commitment.