Insight | Buying supplements well: single ingredients, third-party testing and quality

The Short Version

Andy Galpin, Rhonda Patrick and Abud Bakri each argue, from very different corners, that a supplement or compound is only as good as what is actually in the container: its form, its purity, its freshness and where it came from [1][2][3][4]. Galpin insists on single-ingredient products and third-party certification, pointing to melatonin products so far off their labels that users wake with many times the upper limit in their blood [1]. Patrick shows how much the form and freshness of fish oil matter, checks independent oxidation scores, and urges testing before and after supplementing because, as she puts it, "you can't know what you don't measure" [2][3]. Bakri describes a peptide market that runs from tightly controlled pharmaceutical products to gray-market vials whose contents can vary from batch to batch, and his advice is to avoid research-use websites and work with an informed physician [4].

What They Said

Andy Galpin: one ingredient, verified, for a reason

Andy Galpin, introduced as a professor of kinesiology at Cal State Fullerton, describes himself as a context-and-precision coach who normally gives people only what testing shows they need [1]. With high-performance clients he runs extensive blood, saliva, urine and stool testing and supplements only a specific need; for everyone else, he reluctantly offers a short list of options that are "fairly effective and fairly cheap" [1].

Why the contents matter so much

His starting point explains why quality is not a side issue. Supplements can work, he says, because they deliver nutrients in concentrations you would never get from food, and for the same reason they can be counterproductive or cancel each other out [1].

He also specifies forms. Creatine monohydrate is "always number one on my list," at about 3 to 5 grams a day, and he notes that loading at 15 to 25 grams is unnecessary for most people and that large doses pull water into the gut and cause distress [1]. For magnesium in the recovery stage, he names about 6 mg per kilogram and says citrate has the most evidence [1]. For caffeine, Huberman notes that commercial coffees can contain far more caffeine than standard lookup tables suggest, and that caffeine tablets are the only way to know a dose objectively [1].

Single ingredients "at all costs"

Both Galpin and Andrew Huberman strongly favor single-ingredient supplements, so that you can tell what is working, adjust doses and timing, and trust the label [1]. Galpin explains what goes wrong with combinations using rhodiola, which typically comes mixed with other herbs and "adrenal support" products [1]. "So I think the biggest part of all that is if something doesn't feel good, you have absolutely no idea," one of them says, adding that the culprit could be the rhodiola, any other ingredient, or even the citric acid used in the product [1]. Worse, the conversation adds, you might wrongly conclude that a supplement that actually works for you does not, and drop it for the rest of your life [1]. The conversation puts it plainly: "make sure you're taking single ingredient supplements at all costs" [1].

The conversation adds a reason: "Single ingredient formulations are pretty much the only way to do that," for finding the right dose, taking something on some days and off others, or adjusting morning and afternoon doses [1]. One of them is "not opposed to blends where the blends include a lot of nutrients that are synergistic" [1]. But for targeted, pill-based effects, single-ingredient products are how you build a rational approach and adjust when something is or is not working [1].

He also flags an economic catch: different ingredients cost very different amounts to make, so "blends will include the least amount of the most expensive ingredient," though he notes there are exceptions [1].

Single sourcing and quality

Rhodiola also shows how hard sourcing can be. Galpin says the difficult part is getting it from a high-quality brand and source: "It's difficult to get as a single source, which is a very, very important thing to do with supplements is try to get them sourced alone" [1]. If someone tells him rhodiola did nothing for them, he allows that nothing works for everyone, but adds that it "could be just very poor quality sourcing" [1].

The melatonin problem

Galpin's sharpest example comes from melatonin. He describes studies of off-the-shelf melatonin in which actual doses were wildly off label [1]. He says they see it constantly: "People will have like 500 times the upper limit of melatonin the morning after," even though the half-life "is supposed to be more like 90 minutes" [1]. He is careful about scale: "I'm talking 10, 20, 30, X, the upper limit range for melatonin the next morning" [1]. Asked what they took, people name a product from a store or website [1].

The consequence is a cycle he describes vividly. A cheaper product might mean "you could be totally wrecking yourself by getting, you know, 50 milligrams of melatonin every night and not realizing it," and then drowning yourself in caffeine the next morning [1]. He says he is not opposed to melatonin in theory, but "you have to be careful with that one in particular" [1].

Third-party certification for everyone

Galpin's view on third-party testing tightens during the conversation. Discussing rhodiola, he first says certification is not necessary for most people, "but for any athletes that need to go through drug testing systems, you should not take any supplement at all that does not have some sort of third party certification" [1]. By the time he reaches melatonin, he widens it: buy from high-quality sources and choose third-party tested products "even if you're not a performance athlete, I want to stress this," because certified products are less likely to contain wildly high or low concentrations of active ingredients [1]. The summary records the same conclusion: third-party certification helps everyone, not just drug-tested athletes [1]. One of them adds that people can look for certification on the packaging, and that some websites let you zoom in on the bottle before buying [1].

Need, root causes and dependency

Galpin's quality rules sit inside a larger philosophy. His goal for every client is to need little or no supplementation: "Your physiology is way smarter than we are" [1]. He will use short-term tools to manage symptoms, such as something for sleep, but then hunts for the root cause, from infection, allergens, mold and heavy metals to stress or never seeing the sun or sweating; covering symptoms, he warns, means "you're really missing signal" [1]. Huberman quotes a physician friend: "better living through chemistry still requires better living" [1].

He applies the same thinking to probiotics, advising against random probiotics without a clear purpose [1]. One of them says he takes fewer probiotic pills when he is eating low-sugar fermented foods, and takes them only when compromised [1]. The conversation also raises the hope that companies will offer samples, so people can try something like alpha-GPC before buying a whole product [1]. Both recommend examine.com, unpaid, for dosages and evidence [1].

Rhonda Patrick: form, freshness and testing your own levels

Rhonda Patrick is introduced as a biomedical scientist who did postdoctoral work with Bruce Ames on micronutrients [2][3]. In her conversation with Huberman, she gives the most detailed account of how one supplement, fish oil, can vary in quality, and pairs it with an insistence on measuring rather than guessing [2][3].

Fish oil: the form on the label

The omega-3s that matter, she explains, are EPA and DHA from fatty cold-water fish, not the plant form ALA, which converts poorly [2][3]. Quality fish oil comes in triglyceride form, she says, while cheaper products use an ethyl ester form that is less bioavailable and absorbs poorly unless taken with food [2][3]. Krill oil provides omega-3s in phospholipid form, which is more bioavailable, but she says krill products are very low dose and, in her experience, often rancid [2][3]. Huberman says krill oil made him itchy [2].

For vegans and vegetarians, she recommends algae oil over flaxseed or walnuts, since converting ALA to EPA and DHA is inefficient, sometimes only about 5% [2][3].

Freshness: oxidation and independent scores

Omega-3s oxidize easily, Patrick says, which is why she tells listeners to "please keep your fish oil in the refrigerator" [3]. She checks the International Fish Oil Standards (IFOS) third-party testing site, which reports contaminants and oxidation, and looks for a total oxidation (TOTOX) score under 10, ideally under 6 [2][3]. Her reason for checking is blunt: "nothing is ever what it says on the bottle" [2][3].

Dose: what the label claims versus what you need

Patrick takes about four grams of omega-3s a day, EPA in the morning and DHA in the evening, and says "two grams or more is the magic number" [2][3]. She explains that prescription omega-3s such as Lovaza and Vascepa are prescribed at four grams a day for high triglycerides, a dose that researcher Bill Harris told her reflects cost and compliance, or what patients would realistically take, rather than a safety ceiling [2][3].

The way to find out whether your dose works is to test. She favors the omega-3 index, which measures omega-3s in red blood cells and reflects about 120 days of intake, over plasma tests, which reflect recent meals [2][3]. Moving from about 4% to 8% took roughly two grams a day of supplementation, and Harris co-founded OmegaQuant, which offers blood-spot tests; she suggests retesting after about 120 days [2][3]. Her own index is almost 16% [2][3].

Sourcing food as carefully as pills

The same care extends to food. Patrick eats sardines almost daily but notes that some sardine brands can carry mercury, and she uses ConsumerLab to check [2]. The second summary records that Joe Rogan found high mercury after eating sardines daily, so the brand matters [3]. She recommends wild Alaskan salmon and salmon roe, a rich source of phospholipid DHA [2][3].

Vitamin D: test before and after

Vitamin D is where her testing rule is firmest. She says about 70% of Americans have insufficient levels, below 30 ng/mL, while mortality analyses suggest 40 to 60 ng/mL is ideal [2][3]. Her rule of thumb is that 1,000 IU of D3 typically raises blood levels by about 5 ng/mL, so going from 20 to 40 takes around 4,000 IU daily, but common genetic variants can change that [2][3]. Huberman shares that a family member needed about 30,000 IU a day just to reach normal levels, which is why Patrick insists on testing before and after: "you can't know what you don't measure" [2][3]. She takes 5,000 IU daily and sits around 50 ng/mL, and notes that the official upper tolerable intake is 4,000 IU, though toxicity generally requires extremely high doses over time [2][3].

Magnesium: the form and the gut

Patrick also discusses magnesium forms. She gets most of her magnesium from dark leafy greens and supplements only about 130 to 135 milligrams to avoid digestive upset [2][3]. She notes that citrate is especially hard on the gut and favors malate, which may support gut cells [2][3]. Huberman takes threonate or bisglycinate before sleep and malate during the day, and the evidence on threonate's brain effects is described as promising but still limited [2][3].

Brands, disclosed

She takes a heaping tablespoon of Kuli Kuli moringa powder in smoothies and states she has no affiliation with the brand [2][3]. She also offers a food alternative to a supplement: about one gram of ground mustard seed powder added to cooked broccoli increased sulforaphane about fourfold in one study, because it supplies the enzyme that heat destroys [2][3].

Abud Bakri: when the vial may not hold what it says

Abud Bakri is introduced as a board-certified internal medicine physician who works in hospital wards and ICUs and has deep knowledge of the science and history of peptides [4]. His subject is peptides, not ordinary supplements, but his account of where these compounds come from is the most detailed picture of sourcing risk in these sources [4].

Know what the molecule is

Bakri says there is no real scientific category called peptides: carnosine, BPC-157 and retatrutide share the label but little else, and what matters is which receptor a molecule touches [4]. He separates peptides with clear receptors and predictable effects, like the GLP-1 drugs, from obscure ones like BPC-157, which have no identified receptor [4]. For BPC-157, he adds, the evidence itself is narrow: "All the data comes from one group. So people can be skeptical" [4].

Four tiers of supply

His map of the supply chain runs from most to least controlled. Big pharma products are the most tightly controlled, compounding pharmacies range from excellent to lousy, and research-use-only gray-market peptides vary from batch to batch [4]. "Now, the compounding pharmacies vary in grading. Some of them are really good. They do all the testing, sterility. They have very good quality control," he says [4]. Black-market peptides, bought directly from overseas or made at home, are riskier still [4].

The gray market produces real mix-ups. One man on X said the retatrutide he bought was darkening his skin, suggesting it was actually Melanotan II [4]. Nearly all active peptide ingredients are synthesized in China: "So they're all Chinese peptides. Everything's Chinese peptides" [4]. Bakri estimates $5 to $10 billion was spent on gray-market peptides in the U.S. in 2025, much of it sold by social media affiliates, and says more than half the market is women [4].

Labels shaped by regulation

Bakri explains how regulation reshapes what gets sold. In late 2024, BPC-157 and about 20 other peptides were moved to the FDA's category 2 list, meaning do not compound, and some compounders relabeled BPC-157 as pentadeca arginate, which he says is essentially the same molecule in a different salt [4]. Compounding pharmacies also have to meet rules for a shortage or a patient's unique need, so, he says, "they'll add on a B-12 or a B-6 to say, like, the patient had nausea from the traditional semi-glutide" [4].

Price, markups and who profits

He also points to price as part of quality. During GLP-1 shortages, compounding pharmacies were allowed to make semaglutide and tirzepatide, and he notes that clinicians sometimes marked up compounded drugs heavily [4]. Huberman encourages patients to ask what their doctor pays versus what they charge [4]. Ozempic pens that cost around $1,500 in the U.S. sold for about $150 an hour away in Mexico [4].

Dose uncertainty in practice

Bakri tells a cautionary story about not knowing what is in a product: he once injected a full milligram of semaglutide from a pen a relative thought was fake and vomited through an entire night shift [4]. Both he and Huberman share personal experiments with peptides but repeatedly stress they are not recommendations [4]. Huberman says he has tried BPC-157 through a compounding pharmacy, and that he obtained gray-market products in the past but was too frightened to take them [4].

His sourcing advice

His advice is to avoid research-use websites, build a relationship with a physician who is educated about peptides, expect physician-led and telehealth options to improve, and get lab monitoring, for example IGF-1 when using tesamorelin [4]. Malpractice insurers generally will not cover non-FDA-approved peptides, he notes, and he believes the choice should be a frank, monitored conversation: "It should be between the physician and the patient" [4]. To young gym-goers, he says, "dude, you're 18. You have all the peptides you need in you" [4]. Above all, he says, the basics come first: morning sunlight, sleep, darkness at night and minimally processed food [4].

Where They Agree, and Where They Don't

Where they agree

Labels cannot be taken on trust. Galpin describes melatonin users with many times the upper limit in their blood the morning after [1]. Patrick says "nothing is ever what it says on the bottle" [2][3]. Bakri describes gray-market peptides that vary from batch to batch and a vial sold as retatrutide that seemed to be Melanotan II [4].

Independent verification is the answer. Galpin wants third-party certification for everyone, and mandatory for drug-tested athletes [1]. Patrick checks IFOS oxidation scores and ConsumerLab [2][3]. Bakri points to compounding pharmacies that do full testing and sterility checks, and to lab monitoring under a physician [4].

Form matters. Galpin names creatine monohydrate and magnesium citrate [1]. Patrick distinguishes triglyceride, ethyl ester and phospholipid fish oil and several magnesium forms [2][3]. Bakri insists that what matters is which receptor a molecule touches, not the umbrella word peptide [4].

Measure, do not guess. Patrick urges testing vitamin D before and after supplementing and retesting the omega-3 index after about 120 days [2][3]. Galpin's precision coaching starts from blood, saliva, urine and stool testing [1]. Bakri recommends lab monitoring such as IGF-1 [4].

Basics before bottles. Galpin's goal is for clients to need little or no supplementation and to find root causes [1]. Bakri puts sunlight, sleep, darkness and minimally processed food first [4]. Patrick stresses that supplementing vitamin D does not replace sunlight and gets much of her magnesium from leafy greens [2][3].

Where they differ

Magnesium citrate. Galpin says citrate has the most evidence for magnesium in recovery [1]. Patrick says citrate is especially hard on the gut and favors malate at low doses [2][3]. They are weighing different things: Galpin the evidence base for recovery, Patrick tolerance and gut comfort.

Who needs third-party certification. Within Galpin's own conversation, his view broadens: he first says certification is not necessary for most people but essential for drug-tested athletes, then stresses that even non-athletes benefit because certified products are less likely to be wildly off in concentration [1].

How far personal experiment should go. Bakri and Huberman both describe trying compounds with thin human evidence, such as BPC-157, while stressing these are not recommendations [4]. Galpin's approach is more conservative, using supplements to meet a measured need and looking for the root cause rather than relying on a product [1]. Patrick's experiments are with established nutrients, checked against her own blood levels [2][3].

Why It Works

The sources give several reasons why quality decides outcomes.

Concentration is the point of a supplement. Galpin explains that supplements work because they deliver nutrients in concentrations food never would, which is also why too much or too little can backfire [1].

Half-life reveals overdosing. Melatonin's half-life is supposed to be about 90 minutes, so finding very high levels the next morning signals that people are taking far more than they think [1].

Oxidation and form change what you absorb. Omega-3s oxidize easily, which is why Patrick refrigerates fish oil and checks TOTOX scores [2][3]. Triglyceride-form fish oil is more bioavailable than ethyl ester, and phospholipid omega-3s more bioavailable still, though krill products tend to be low dose [2][3].

Single ingredients let you learn from your body. With one ingredient, Galpin says, you can tell what caused a good or bad reaction, while a blend leaves you guessing and may make you abandon something that works [1]. Huberman adds that single ingredients make it possible to adjust doses and timing [1].

Blend economics. Huberman says blends often include the least of the most expensive ingredient [1].

Individual biology varies. Genetic variants change how much vitamin D a given dose produces, and one person needed about 30,000 IU a day to reach normal levels, which is why testing beats assuming [2][3].

Supply chains and regulation shape the product. Bakri describes compounds synthesized overseas, compounders adding vitamins to meet regulatory rules, relabeling after FDA category changes, and gray-market batches that vary, all of which affect what reaches the buyer [4].

Where It Applies, and Where It Doesn't

Drug-tested athletes. Galpin's rule is absolute here: take no supplement at all without third-party certification [1].

Everyday supplement users. Galpin's later advice and Patrick's habits apply to anyone buying melatonin, fish oil, vitamin D or magnesium: choose certified, well-formulated products and test where you can [1][2][3].

Vegans and vegetarians. Patrick's advice to choose algae oil over plant ALA sources applies specifically to people who do not eat fish [2][3].

People with variable responses. People with darker skin, older adults and those with genetic variants make or convert vitamin D less efficiently [2][3].

Peptides are a different category. Bakri's sourcing advice applies to compounds with thin human evidence, an unsettled legal status and supply chains that include gray and black markets [4]. Nothing in his episode is a recommendation to use these compounds [4]. The stakes there are higher than with a mislabeled vitamin, which is why he insists on a physician and lab monitoring [4].

Where the sources stop. Huberman notes there are exceptions to the blend-economics rule [1], and Patrick's views on threonate and red light are explicitly tentative [2][3]. Before starting supplements, especially at high doses or alongside medication, talk to a doctor who can order the relevant blood tests.

What To Do With It

1. Buy single-ingredient products for targeted goals. Follow Galpin's rule so you can tell what is working, adjust doses and drop what is not [1].

2. Look for third-party certification on the label. Galpin says certified products are less likely to be wildly off in concentration, and the conversation suggests zooming in on the bottle online before buying [1].

3. Be especially careful with melatonin. Galpin has seen next-morning levels many times the upper limit from off-the-shelf products; choose a certified, high-quality source [1].

4. Check the form before the price. Choose creatine monohydrate [1], triglyceride-form fish oil over ethyl ester [2][3], and a magnesium form you tolerate, whether citrate for recovery evidence or malate for an easier gut [1][2][3].

5. Check fish oil freshness. Look up IFOS results for a TOTOX score under 10, ideally under 6, and keep the bottle in the refrigerator [2][3].

6. Test before and after. Measure vitamin D before and after supplementing, and test the omega-3 index before and again after about 120 days to see whether the dose worked [2][3].

7. Use dose rules as starting points, not answers. Patrick's estimate that 1,000 IU of D3 raises blood levels about 5 ng/mL can be thrown off by genetics, so let your test results decide [2][3].

8. Be wary of blends that hide expensive ingredients. Huberman warns that blends often include the least of the costliest ingredient [1].

9. Avoid research-use and gray-market sources for peptides. Bakri advises working with an informed physician and getting lab monitoring, and Huberman encourages asking what your clinician pays versus what they charge [4].

10. Start with the basics and the root cause. Fix sleep, light, food and stress first, and use supplements to meet a real need rather than to cover a symptom, as Galpin and Bakri both urge [1][4].

Sources

1. Dr. Andy Galpin: Optimal Nutrition & Supplementation for Fitness · Huberman Lab
2. Dr. Rhonda Patrick on Micronutrients, Omega-3s, Vitamin D, Cold and Sauna for Health and Longevity · Huberman Lab
3. Dr Rhonda Patrick Micronutrients For Health Longevity · Huberman Lab
4. Dr. Abud Bakri on Peptides: BPC-157, Thymic and Russian Bioregulators, GHK-Cu, Growth Hormone Secretagogues and GLP-1s · Huberman Lab