I’m a Dietitian—Here’s How to Tell If a Supplement Is Actually High Quality

I evaluate supplements for a living as a dietitian and Good Housekeeping’s Nutrition Director, and if there’s one question I hear all the time, it’s: “Which supplements should I be taking?” I used to roll my eyes, but after learning what I know now, I realize there’s so much misinformation about supplements out there. People genuinely don’t know what they should be taking, or if they should be taking anything at all.

What’s more, supplements are everywhere, from grocery store aisles to Amazon and even TikTok Shop. I mean, Procter & Gamble just acquired supplement maker Thorne for nearly $4 billion—yes, you read that correctly! It seems like there’s a new supplement launching every day, another influencer promoting their favorite vitamin gummies, and someone on a podcast explaining how a supplement “changed their life.” But instead of asking what you should be taking, the bigger question is whether or not this stuff is actually worth the hype.

My short answer: I do believe supplements can play an important role in a healthy lifestyle. The key word, though, is supplement—they’re meant to complement a nutritious diet and healthy lifestyle, not replace them. There’s no one-size-fits-all approach, either, because what makes sense for one person may not be right for someone else. Supplements can be helpful tools when used intentionally, but they aren’t automatically better because they’re popular, expensive, or have impressive claims on the label. Ahead, I’ll share my checklist for evaluating a supplement and determining whether it’s safe, high quality, and right for you.

Our registered dietitians in the Good Housekeeping Institute Nutrition Lab review and evaluate every single supplement we recommend in accordance with our dietary supplement methodology. We then have a registered dietitian on our Medical Review Board review each article for scientific accuracy. A supplement should do just that: supplement the diet, not replace high-quality, nutritious food and important healthy lifestyle practices. Check with your healthcare provider before starting any dietary supplement regimen.

The first thing I look at when evaluating a supplement has nothing to do with the bottle itself. Before I look at the ingredients, the brand, or the claims on the label, I ask one simple question: Do I have a clear reason for taking this?

This might sound obvious, but it’s honestly the most important step (and one that often gets skipped). A supplement should have a purpose. Maybe bloodwork showed a deficiency, or perhaps your diet has a specific gap. Maybe you’re in a stage of life where your nutrient needs have changed, such as pregnancy or intense athletic training. Maybe your doctor recommended it based on your individual lifestyle and medical history.

Remember, more isn’t always better when it comes to nutrition. The goal isn’t to take the most supplements possible, but rather to identify what your body actually needs and choose accordingly. Don’t just take something because it’s trending or someone online swears by it.

Once I know there’s a reason to consider a supplement, the next thing I look at is the evidence. In my time as a dietitian, digging into the research, I’ve realized that just because an ingredient is popular doesn’t mean it’s proven.

The supplement industry moves quickly, and marketing often moves even faster. There are always new “must-have” ingredients promising incredible results, but I want to know what the research actually shows.

I look for ingredients that have evidence supporting their safety and effectiveness, ideally from well-designed human studies. A solid free resource is the National Institutes of Health (NIH) Office of Dietary Supplements. I also pay attention to whether the amount included in the supplement is actually meaningful. This is where a lot of people get tripped up, because a supplement boasting “500% of your Daily Value” may sound impressive, but a bigger number doesn’t automatically mean a better product. The right dose depends on the nutrient, the reason you’re taking it, and your individual needs. Sometimes too much can build up in your body, and other times, excess is excreted, so it’s really a waste of your money.

Instead of the biggest dose possible, you have to find the right dose for you. If you’re not sure what that is, speak with your doctor or dietitian, who should be able to guide you. When I was deficient in vitamin D several years ago, my doctor gave me a specific dose to take daily and then we retested after a period of time when she then adjusted the dose. The point is that the dose may change based on your bloodwork, so it’s important to reassess if you are taking something for a long time, too.

The front of a supplement bottle is designed to catch your attention, but the back of the bottle is where you find the information that actually matters. On the Supplement Facts panel, I look at things like:

• What ingredients are included?
• How much of each ingredient is in the product?
• Are the forms of the nutrients appropriate?
• Are there unnecessary extras?

One thing I think is especially important is bioavailability, which essentially means how well your body can absorb and use a nutrient. Not all forms of a nutrient are created equal. The form of an ingredient can impact absorption, effectiveness, and how well someone tolerates it. For example, different forms of minerals or vitamins may behave differently in the body, which is why I don’t just look at the number on the label, but rather what form that number represents.

I also prefer supplements with simple, intentional ingredient lists. A longer ingredient list doesn’t automatically mean a better supplement. I’m usually cautious of products with proprietary blends that don’t clearly disclose ingredient amounts, unnecessary fillers, artificial dyes, and artificial flavors. A quality supplement really doesn’t need to be a complicated formula to be effective.

This is by far my biggest consideration when purchasing or recommending a supplement. Because when we buy a supplement, we’re trusting that what’s listed on the label is actually what’s inside the bottle. But unlike medications, dietary supplements don’t have to be approved by the U.S. Food and Drug Administration (FDA) before hitting store shelves. That means quality control and transparency from the company matter.

One of the biggest things I look for is quality third-party testing. This means an independent organization evaluates the product to help verify things like purity, potency, and quality. Some examples of respected third-party organizations include USP and NSF. And while a third-party seal is helpful, I also want to know:

• Does the company provide Certificates of Analysis (COAs)?
• Are they transparent about where ingredients come from?
• Do they explain their manufacturing practices?
• Are their claims realistic?

A company that prioritizes quality should make it easy for people to find this information. If I have to dig endlessly to figure out what’s actually in a product or how it was tested, or if the answers are vague, that’s usually a red flag to me.

Supplements can be a huge investment, and their cost varies greatly. Now, some more expensive options can be worth it, but other more affordable picks can also be high quality.

When I evaluate the value of a supplement, I zero in on the serving size. How much does it cost per serving? Is the serving size realistic? And most importantly, will I actually take it consistently, and does it fit into my lifestyle? Because at the end of the day, the best supplement in the world doesn’t matter if it’s sitting untouched in your cabinet.

A quality supplement should be something that makes sense for your needs, your budget, and your routine. If you’re more likely to stick with taking a gummy vitamin, then maybe that’s worth the extra few dollars over a capsule. It boils down to your preferences and needs.

Supplements can absolutely be useful tools, but they should be chosen carefully and intentionally. Before adding one to your routine, think about whether you actually need it, whether there’s solid evidence behind it, whether it’s formulated well, whether you can trust the brand and its quality standards, and whether it’s truly worth the cost for you.

In my experience as a registered dietitian, I’ve found that the best supplement isn’t the one with the biggest claims, the trendiest ingredient, or the highest price tag. It’s the one that has a clear purpose, is backed by evidence, meets quality standards, and makes sense for your individual needs. So before you spend your hard-earned money, make sure it’s a product you can actually trust.

As director of the Good Housekeeping Institute Nutrition Lab, registered dietitian Stefani Sassos, M.S., R.D.N., C.D.N., handles all nutrition-related content, product testing, and evaluation. She stays up to date on the latest research to provide evidence-based reporting on all things diet and nutrition. Stefani oversees supplement analysis for Good Housekeeping and has evaluated categories including multivitamins, joint health supplements, and vitamin D.

Medically reviewed byGillean Barkyoumb, MS, RDN

Gillean is a media dietitian with over a decade of experience working with brands through TV, content creation, and consulting. She’s the founder of the What’s for Dinner Club, a resource that provides healthy, easy dinner recipes for busy families. As a mom of 3, she knows how overwhelming it can feel to make your nutrition and priority, so through her work she strives to make nutrition simple and convenient. Gillean is also the co-founder of a media training program called Expert with Influence, with the goal of helping health experts grow in the media space and be a source of reliable, credible nutrition information.