Supplements Beyond Heart Disease: What Creatine Tells You About the Rest

Even the strongest case for a supplement is pretty weak

Top-selling creatine supplement on Amazon: No seal verifies that it actually works.

In my last post I argued that supplements marketed for heart disease do not work. The question that follows, and I hear some version of it almost every week in clinic, is “Fine, but what about everything else?” There are thousands of products on the store shelves, far too many to take up one at a time, and for most of them I have no strong opinion other than “probably a waste of money.” So rather than work through a list, I will use a single example: creatine, because it is among the few supplements with any real research data from studies that have evaluated it. If the case is thin for creatine, that tells you most of what you need to know about the rest.

Creatine

I am not a big fan of creatine. In a person with normal kidney function, it probably is harmless. My primary hesitation is that the supplement industry is regulated far less rigorously than the pharmaceutical industry. Because it lacks routine premarket FDA review of safety, efficacy, and product quality, I never am fully confident about the dose or purity of what a given patient actually is taking (1,2). One clarifying note before going further: creatine is the supplement, and creatinine is the muscle breakdown product measured in a clinical chemistry lab and used to assess kidney function. The two are connected: creatine supplementation can push your serum creatinine modestly upward, because some of it is converted to creatinine and adds to the blood pool, without any true decline in kidney function (3,4). If your serum creatinine level goes up and you take this supplement, tell your physician before embarking on a detailed work-up.

As for a possible benefit of creatine supplements, certain preparations at high doses have been shown to increase maximum weight-lifting reps, which can serve as a stimulus to muscle growth (5). For a competitive bodybuilder, that margin may be worth chasing. But for most people it sits well down the list, behind the two interventions that actually do the work: consistent resistance training and adequate protein intake. I will concede that in older adults trying to not lose muscle, for whom sarcopenia can be a genuine clinical problem, some data on resistance training combined with creatine suggest some benefit, although the data are quite weak. Two analyses of pooled randomized trials in adults roughly 55-70 years old found that creatine added to resistance training produced about 3 pounds more lean tissue mass and greater strength on chest press and leg press than training alone (6,7). That may sound impressive, but these two meta-analyses drew from largely the same small pool of trials and many of those trials were authored by the same group of investigators, so they are not truly independent confirmations. Furthermore, the individual studies were small (typically 12-40 people per arm), of very short duration (range 7-16 weeks, average around 12-13 weeks), and blinding was questionable, because creatine causes water retention and early weight gain that people can notice. Indeed, water retention can bias lean mass measurements, so some of the lean mass gain likely reflects intracellular water, not new muscle protein. The strength results were uneven, with improvements on chest press and leg press but not on knee extension, biceps curl, or isometric torque measures. This is considered low to very low-quality data.

So, I don’t dismiss the idea that creatine may help older adults who are doing resistance training, but let’s not overstate the case. Creatine may have a modest effect, based on a thin, low-quality evidence base. Consistent training and adequate dietary protein intake are the interventions that do the real heavy lifting (pun intended).

The Bigger Concern: Safety, Cost, and Distraction

The bigger problem with supplements is the unknown safety of what you actually buy on the shelf or online, together with the expense and the distraction from things that really work, which might not be as easy to implement as swallowing a pill.

If you do decide to take a supplement, look for third-party product verification, such as NSF International (formerly the National Sanitation Foundation) or USP (United States Pharmacopeia) certification. These programs test the finished product to confirm that it contains what the label says, in identity and in potency (8,9). Both screen for heavy metals, microbes, and certain toxins, and both audit the manufacturing facility for GMP (Good Manufacturing Practices) compliance. NSF “Certified for Sport” adds screening for substances banned in competitive athletics, which is worth knowing if you are subject to drug testing (8,9).

But you must understand what these certifications do not tell you. They are voluntary and paid for by the manufacturers. They test batches rather than every bottle, and they test periodically rather than continuously, so batch-to-batch variation between audits goes unmonitored. They confirm identity and potency, but they do not verify efficacy or safety claims.

And like any analytical screen, they test against a known panel of contaminants, which is useful for catching established problems, but not a guarantee against a novel adulterant that no one is looking for yet (9). What you get is a somewhat lower risk of gross contamination or outright mislabeling. They are not, however, the equivalent of FDA oversight of a prescription drug, and no seal on a bottle should be read that way.

So my answer to “what about everything else?” is close to my answer about heart disease supplements. Most - nearly all - are unnecessary or unhelpful and some are harmful. But if you still choose to take one, remember that the seal on the label is modest protection against contamination, nothing more. Supplements remain an expensive distraction from the things that truly work and are proven safe.

References

1. Geller AI, Shehab N, Weidle NJ, et al. Emergency department visits for adverse events related to dietary supplements. N Engl J Med. 2015;373(16):1531-1540. doi:10.1056/NEJMsa1504267.

2. Tucker J, Fischer T, Upjohn L, et al. Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings. JAMA Netw Open 2018;1:e183337. doi:10.1001/jamanetworkopen.2018.3337.

3. de Souza E Silva A, Pertille A, Reis Barbosa CG, et al. Effects of creatine supplementation on renal function: a systematic review and meta-analysis. J Ren Nutr 2019;29(6):480-489. doi:10.1053/j.jrn.2019.05.004.

4. Naeini EK, Eskandari M, Mortazavi M, et al. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC Nephrol 2025;26:622. doi:10.1186/s12882-025-04558-6.

5. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 2017;14:18. doi:10.1186/s12970-017-0173-z.

6. Devries MC, Phillips SM. Creatine supplementation during resistance training in older adults: a meta-analysis. Med Sci Sports Exerc 2014;46(6):1194-1203. doi:10.1249/MSS.0000000000000220.

7. Chilibeck PD, Kaviani M, Candow DG, et al. Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med 2017;8:213-226. doi:10.2147/OAJSM.S123529.

8. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need to Know. https://ods.od.nih.gov/factsheets/WYNTK-Consumer/. Accessed July 13, 2026.

9. Akabas SR, Vannice G, Atwater JB, et al. Quality Certification Programs for Dietary Supplements. J Acad Nutr Diet 2016;116:1370-1379. doi:10.1016/j.jand.2015.11.003.