Increased absorption and bioavailability are only some of the benefits of water-soluble CBD, the oil alternative
Buying CBD in the U.S. today can be a dizzying experience. The sheer volume of products is overwhelming, many of which claim to have unique and distinctive properties. Among the newer CBD products on the market are those with water-soluble CBD, which claim to offer better absorption and to be more bioavailable to the body. That is, they are supposed to more readily enter into circulation and exert a greater therapeutic effect.
Water-soluble CBD is different from traditional CBD in that it mixes easily with water. CBD, by nature, is not water-soluble — it is “lipophilic” and dissolves in oil. This is because the CBD molecule actually is an oil, and as fats, oils don’t dissolve in water.
CBD oil to water
How does CBD in its original oil, or oil-soluble, form get converted into water-soluble CBD?
“It is a bit like a Trojan horse, meaning we bind or ‘hide’ the micro-sized oil droplets within small bubbles, known as micelles,” says Scott Riefler, chief science officer at SōRSE Technology, a water-soluble CBD manufacturer. “The micelles are constructed of water-loving materials. In this application the micelles are designed to tightly bind and isolate the oils in a manner that they present as water-soluble.”
These are also often referred to as nano-emulsions. This processing makes it possible for CBD in water-soluble products to dissolve in the blood. It is also why they can be mixed into liquids without the separation that would occur if you added oil-soluble CBD.
How CBD is taken and absorbed
When CBD is being consumed orally, it has to go through the same process of digestion and absorption as anything else. In this way, water-soluble CBD could be compared to water-soluble nutrients like vitamin B12 or carbohydrates, while oil-soluble CBD could be compared to fat-soluble nutrients like vitamin E or cholesterol. Since the majority of the body is water, it’s not surprising that the digestion and absorption of water-soluble molecules is easier than for oils.
Water-soluble molecules get absorbed through the wall of the small intestine into the intestinal cells, and then they pass into the hepatic portal vein, which carries them to the liver. In the liver there is metabolism of many molecules, including CBD, before they get out into general circulation. This is called “first-pass metabolism,” and it involves chemical reactions that greatly reduce the amount of the molecule that gets distributed throughout the body.
Small fats also travel to the liver through the hepatic portal vein, while larger fat-soluble molecules (like CBD oil) get to the liver via a different route. After larger fats get absorbed, they are incorporated into carrier molecules called chylomicrons that travel through the lymphatic system, which is similar to the circulatory system but contains lymph fluid instead of blood. The lymph then “dumps” into the general circulation, and the chylomicrons travel to the liver, where the fat-soluble molecules also go through first pass metabolism.
Both oil-soluble and water-soluble molecules end up in the liver, but they take slightly different routes.
At this point, you may be asking, “Where do differences in bioavailability come from? Both water- and oil-soluble molecules are absorbed, travel to the liver and are distributed throughout the body.” Many of the differences happen at the level of absorption, with oil-soluble CBD showing wide variation depending on how it is consumed.
When taken on an empty stomach, studies have shown that its bioavailability is only about 6%. If taken with a high-fat meal, however, bioavailability goes up fourfold.1 This characteristic of oil-soluble CBD is similar to what we see with fat-soluble vitamins, which is why nutritionists and dietitians recommend always taking supplements of vitamins A, D, E and K with meals containing fat.
Although studies have not yet looked at how water-soluble CBD absorption is affected by food, if we look at water-soluble nutrient research we see that these are generally very well absorbed, with absorption sometimes better when taken on an empty stomach. The really small size of the emulsified water-soluble CBD particles also means that absorption into the body occurs more readily in locations like the mucous membranes of the mouth, with some suggesting that they may even bypass first-pass metabolism in the liver to an extent.
Water-soluble CBD: increasing bioavailability
The claim of increased bioavailability for water-soluble CBD is made by many companies, most of which do not support their statements with research — but some companies are backing it up with research.
One company has published two studies measuring the bioavailability of their formulations in comparison to traditional CBD. In the first study, 10 healthy adults took a 30-milligram dose of either water- or oil-soluble CBD. The water-soluble CBD was absorbed much faster and was found to be 4.5 times more bioavailable than the oil-soluble CBD.2,3
In the second study, 15 healthy adults consumed CBD in five different formats. The dissolvable CBD powder and liquid concentrate were absorbed significantly better than the two controls, which included an oil-based CBD and a CBD isolate.4,5
What is interesting about this study is that it used a crossover design, in which each subject consumed all five of the products in a randomized order. This type of design helps reduce the variation introduced when each treatment group contains different subjects.
The other company studying pharmacokinetics recently conducted a study comparing 100mg of their dissolvable CBD isolate powder to an equal dose of CBD dispersed in sesame oil. Sesame oil has been shown to increase the absorption of oil-soluble CBD,6 so this would be considered a highly absorbable oil-soluble CBD control group. The water-soluble CBD was absorbed faster and reached higher peak concentrations than the highly absorbable oil-soluble CBD, showing better bioavailability. Although this study is currently unpublished, the consistency of the findings from the three human studies shows the superior absorption of water-soluble CBD.
In addition to increased bioavailability and absorption, there are also several other reported advantages to water-soluble products. Research showed that the rate of absorption of water-soluble CBD was faster, meaning the user will experience faster-acting effects. And since water-soluble CBD absorption is less affected by factors like taking it with a meal, especially one containing fats, the dosing is more consistent. As well, water-soluble products are more stable; oils are vulnerable to a process called oxidation that happens naturally over time, especially in the presence of sunlight or heat. When made water-soluble, the CBD has a longer shelf life, although it will still have an expiration date. Finally, many consumers like the convenience and taste of water-soluble CBD. It can be added to any beverage, and most are tasteless and odorless, unlike CBD oil, which (depending on the preparation) may have a strong taste. Oil is also, well, oily, which is unpalatable to some.
Isolates and spectrums
Water-soluble CBD products are available both as isolates, which contain only CBD, and full- or broad-spectrum preparations that also contain other molecules from the cannabis plant, like other cannabinoids. As with any other CBD product, it’s critical to look for water-soluble CBD that has undergone third-party testing to validate its quality, purity and potency, and that has a certificate of analysis showing its detailed chemical composition.
A more rapid onset with consistent and convenient dosing is especially useful when treating conditions like pain, sleep and anxiety disorders. Water-soluble CBD offers many benefits, and is a viable alternative to traditional CBD products.
GENEVIEVE NEWTON, DC, PhD, has spent the past 19 years as a researcher and educator in the field of nutritional sciences. A series of personal health crises led her to discover the benefits of cannabinoids, and she soon found herself engrossed in studying the endocannabinoid system and therapeutic applications of cannabis/cannabinoids in mental health, pain, sleep and neurological disorders. She has recently taken a position as the scientific director at Fringe, a new medical CBD and education company. Learn more at joinfringe.com.