Last updated: March 18th, 2021
With so many dietary supplement forms available, you may have questions such as “What is a tincture?”, “What’s the difference between capsules vs. tablets?”, or “Which form is easiest to swallow?”
In this article, we provide an overview of dietary supplement delivery formats, including some key pros and cons of each one to keep in mind.
What is a dietary supplement?
According to U.S. federal regulations and the National Institutes of Health, a dietary supplement is defined as a product that contains one or more dietary ingredients, is taken orally (by the mouth), and is intended to supplement the diet. Dietary ingredients that can be found in supplements include herbs or botanicals, amino acids, vitamins, minerals, and many other ingredients, as well as components of these ingredients. According to regulations, these products must include the term “dietary supplement” on the front panel of the supplement label. (15)
Dietary supplement delivery formats
There is a wide range of delivery formats for oral supplement formulations, such as capsules, tablets, softgels, powders, liquids, and energy bars. Natural health products are also available in other formats, which are not technically defined as supplements, such as via intravenous (IV vitamin therapy) and topical applications (applied to the skin).
Oral dietary supplement forms
During product development, supplement manufacturers consider many factors when selecting delivery forms. Supplements may be better suited to certain delivery forms based on many factors, such as their stability, uniformity, user experience, release time, and resistance to the gastrointestinal environment. (5) The formulation of a dietary supplement may affect the product’s bioavailability, which refers to the proportion of the active ingredient that is absorbed and used by the body. (16)
Similarly, there may be various reasons why an individual may prefer one delivery format over another. We outline common dietary supplement forms and considerations below.
Capsules vs. tablets: what’s the difference?
Capsules and tablets are both common oral pill formats. Capsules consist of a hard, smooth casing, that is filled with the powder or liquid oil of the supplement ingredient(s). Capsules may be made with a gelatin casing, referred to as gelcaps, or a plant-derived source, referred to as veggie caps. Also called phytocaps, veggie caps are commonly made of vegetable cellulose, an insoluble carbohydrate. Often, capsules are filled with only the active ingredient in powder or granules; however, some products may also contain fillers such as cellulose.
Supplements in larger capsules may be difficult to swallow. However, the capsule shell ensures that bitter or unpleasant tasting ingredients aren’t tasted in the mouth. (1)
Tablets, on the other hand, are produced by compressing the powder or granules of the active ingredient with or without excipients. (12) Excipients are ingredients used as fillers, binders, and bulking agents, or to otherwise assist in the manufacturing process or improve the finished supplement product. (6) For example, vitamin C tablets may contain additional ingredients such as cellulose, silicon dioxide, magnesium stearate, and stearic acid as components of the tablet.
Tablets allow the supplement ingredients to be concentrated, which generally results in a higher dose in the finished product when compared to a capsule or softgel. Depending on the supplement, certain tablets may be split or crushed, making them easier to take for individuals who have difficulty swallowing pills. However, certain ingredients have an unpleasant taste, which can be noticeable when taking the supplement in tablet form. (1)
Did you know? In 2013, the National Institutes of Health launched the Dietary Supplement Label Database (DSLD), a tool that allows individuals to search for information on supplement labels of almost all products sold in the U.S. supplement market. (13) According to the DSLD, 48% of all products are in capsule form and 22% are in tablet form. (16)
What is a softgel?
Softgels are a form of pills that contain a liquid supplement ingredient within a gelatin capsule, which is commonly derived from beef or pork gelatin. The gelatin shell helps to protect the contents against spoilage from oxidation and UV rays. Softgels are considered to be easier to swallow than capsules and are generally tasteless or have a mild taste from the softgel casing. (1)
What are chewable tablets?
Chewable tablets, such as chewable vitamin C, are designed to be chewed and broken down in the mouth prior to swallowing. Chewable tablets are often flavored and colored with natural and/or artificial ingredients, such as sweeteners. Chewable tablets provide a solution for individuals who have trouble swallowing, and the taste is intended to make taking supplements more appealing, such as with chewable vitamin C for children. (1)
What are gummy vitamins?
Similar to chewable tablets, supplements in gummy formats, such as gummy vitamins, are designed to provide a convenient and tasty way to take the supplement. Approximately 1% of dietary supplements in the United States are sold in gummy format. (16) In addition to individual gummy vitamins, such as vitamins C or D gummies, you may often see multivitamins, fish oil, and melatonin gummies.
What are powder supplements?
Supplements in powder form make up approximately 14% of supplements available in the United States. (16) Powders are typically dissolved in water or another liquid when they are taken. Unlike capsules or tablets, they do not need to be disintegrated during digestion, so they are considered to be more easily absorbed. A powder format can also provide a higher dose than supplements in pills, reducing the need to take multiple capsules or tablets. (8) Common examples of powders include probiotic powder and protein powder.
Did you know? According to the 2020 Council for Responsible Nutrition Consumer Survey on Dietary Supplements, the top three factors that influence consumer delivery form preferences are ease of swallowing, price, and format. (4)
What are liquid supplements?
Liquid supplements include a variety of products such as vitamin d drops, other liquid vitamins, liquid melatonin, and liquid iron supplements. Unlike powders, liquid vitamins and other liquids do not need to be mixed into water. Individuals with difficulty swallowing pills may prefer to take supplements in liquid form. Liquid supplements are considered to have a high bioavailability; (7) however, research suggests that the carrier (ingredient to assist supplement delivery) can affect the product’s bioavailability. (10)
For example, a review of vitamin D absorption studies compared the absorption rate of vitamin D supplements when combined with different carrier ingredients, including oil, ethanol (alcohol), cellulose, and lactose. The vitamin D supplements with oil and ethanol carriers were in the form of liquid vitamin D drops, while the vitamin D supplements with cellulose and lactose powder carriers were in tablet form. Supplementation with oil-based carriers was associated with the greatest increase in serum (blood) vitamin D levels. (10) You’ll commonly see fat-soluble vitamins and other fat-soluble ingredients in an oil carrier, either in liquid form or as softgels.
What is a tincture?
A tincture is a type of liquid herbal extract that is manufactured by soaking herbs in a liquid base over a period of several weeks, which is then strained to remove the plant material. (3) Tinctures are traditionally manufactured with an alcohol base, although alcohol-free varieties are made using vinegar or glycerin. Alcohol helps to extract the active components of the herb and also acts as a preservative in the finished product. (17)
Herbal tinctures are generally taken on their own or diluted in a small amount of water; however, some herbal tinctures have a strong or bitter taste that may be unpleasant. The liquid format allows for the dose to be carefully adjusted if required. For more information on medicinal herbs and their forms, visit the Fullscript blog.
What are energy bars?
Energy bars are food-based supplements that provide varying amounts of carbohydrates, proteins, and fats as a source of calories for energy. Energy bars may also be fortified with additional nutrients, such as vitamins and minerals. Energy bars are commonly used to support athletic performance by replacing calories used during physical activity, particularly in endurance activities such as ultramarathons. (18) Energy bars and other food-based supplements, such as energy gels and energy drinks, are commonly used for their taste and convenience.
What about novel delivery forms?
Supplement manufacturers are innovating several new dietary supplement delivery formats, which are largely tied to consumer demand for portability and convenience. (5) New delivery formats include:
- Chewable softgels
- Liquid stick packs, designed to dissolve in a bottle of water
- Orally disintegrating powders in stick packs
- Orally disintegrating tablets (e.g., sublingual tablets)
- Sprays (5)
Other delivery formats
Other natural health products are used as alternative delivery formats to oral supplementation, including IV vitamin therapy and topical cream products.
IV vitamin therapy
Intravenous vitamin therapy, known as IV vitamin therapy, is a treatment that involves injecting a liquid solution of micronutrients into the bloodstream intravenously. The IV solution may contain primarily one vitamin, commonly vitamin C, or a combination of water-soluble vitamins, minerals, or other compounds. (2) Intravenous administration of nutrients has been shown to significantly increase plasma levels of the injected ingredient to levels that cannot be obtained through oral supplementation. (14)
The role of high-dose IV vitamin C therapy in health and disease has been investigated since approximately the 1970s. Despite this, evidence on the health effects of IV vitamin therapy is mixed, and there are currently no standardized recommendations. (19)
Transdermal products, which include topical cream, gel, and lotion, are applied to and absorbed by the skin. These products are designed to bypass the gastrointestinal tract in order to increase the absorption of the active ingredient(s). (9)
Research has examined whether ingredients in topical cream products are, in fact, absorbed through the skin into circulation in the body. A review study that examined the effects of transdermal application of magnesium found that magnesium topical cream application is associated with a clinically relevant increase in blood magnesium levels. (9)
Topical creams with certain dietary ingredients are also used to address skin issues. For example, a review that assessed the effects of zinc-containing topical creams found that various zinc creams were effective in treating skin conditions such as localized psoriasis and eczema. (11)
The bottom line
The various forms of dietary supplements each come with their own pros and cons. When selecting dietary supplements, you should consider how these factors will align with your individual preferences, lifestyle, and wellness regimen. Speak to your integrative healthcare practitioner about which dietary supplements and forms are best for you.
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- Office of Dietary Supplements. (n.d.). Dietary Supplement Label Database (DSLD). https://ods.od.nih.gov/Research/Dietary_Supplement_Label_Database.aspx
- Office of Dietary Supplements. (2020a, February 27). Vitamin C. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
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