Do Supplements Work?: The Scientific Evidence of Dietary Supplements

From herbs and botanical extracts to amino acids and fish oil, the supplement industry is vast and easily accessible to consumers. More than half of North Americans report that they use dietary supplements regularly. (6) Common reasons patients take dietary supplements include promoting general health, addressing nutrient gaps in their diets, and lowering their risk of chronic diseases. (3) 

With supplements accounting for a $50 billion (USD) industry, it’s important to know the health benefits of taking supplements and how to choose effective supplement ingredients. (7)(13) Do supplements work? Read on to find out. 

Do supplements work?

Certain supplements can support optimal health, but much of the current research on dietary supplements is mixed. Certain nutrients, such as vitamins and minerals, have been researched significantly more than other supplements, such as herbs. (3) Additionally, the supplements that do have substantial studies often still have unclear quality, dosage, and safety recommendations—all factors that can significantly impact their effectiveness. (8)

Did you know? A report published by the National Institutes of Health found that less than 22% of dietary supplement research was conducted on botanical ingredients. (3)

While more research is needed to understand the role of supplements for disease prevention in otherwise healthy individuals, many supplements have demonstrated their health benefits in observational and randomized controlled trials. (16) 

3 supplements with evidence-based health benefits

Although not all supplement health claims are scientifically proven, some supplements have demonstrated positive health effects. Below are just a few examples of supplements with reliable scientific evidence. 

1. Vitamin and mineral supplements

The most widely used supplement type in the United States, most multivitamins contain about ten vitamins and ten minerals. (9) Research indicates that taking 100% DV vitamin or mineral supplements can increase suboptimal levels of essential nutrients. This can be particularly beneficial for individuals at risk for nutrient deficiencies, such as children, older adults, or those following restricted diets. (2)

2. Fish oil 

Fish oil is another one of North America’s most commonly consumed nutritional supplements. (4) Regularly eating omega-3-rich oily fish (e.g., salmon) is strongly associated with reduced risk of adverse cardiovascular events. (10)(14)

Supplementing with fish oil and omega-3 fatty acids may have similar heart-healthy benefits. Consistent evidence demonstrates that taking fish oil supplements can significantly reduce blood triglyceride levels. (1) Having high blood triglycerides can increase the risk of heart disease and stroke. (12)

3. Whey protein

Many clinical trials indicate the potential benefits of whey protein for muscle growth and weight management. (11) When combined with resistance training, whey protein supplement use can improve body weight, support fat loss, and increase muscle size. (5)(15)

To explore the research on several common supplement types, visit Fullscript’s Ingredient Library.

Determining supplement effectiveness 

Supplement companies often make promising health claims, but understanding the science behind these claims is the best way to determine the effectiveness of a supplement ingredient or formulation. Use the following tips to understand the efficacy of a dietary supplement:  

• Use reliable websites, such as PubMed, to find peer-reviewed scientific evidence.
• Consider using Fullscript’s practitioner resources, such as protocols and the Ingredient Library.
• Refer to the scientific evidence from randomized controlled trials and meta-analyses over observational studies. 
• Use high-quality supplements with the same ingredient part, strain, or species that was researched. 

The bottom line

Supplements are no magic pill, but some can potentially support specific aspects of health, such as preventing nutrient deficiencies and supporting cardiovascular and metabolic health. Although some supplements have ample research, others have little. Studies also vary significantly in research methods and dosage and quality standards for the supplements, often making results unclear. Analyzing scientific evidence about a particular ingredient using reliable websites is the best way to decide if a supplement will work for your treatment goals.