Herbal Capsules: How They're Made

An Herbs for Health editor learns how fresh herbs are turned into herbal supplement tablets and capsules.


Powdered herbs go into the funnel of the encapsulating machine, which can tamp powder into as many as 60,000 empty capsules an hour. Once herbs are ­encapsulated, they are rolled out onto a conveyor belt for ­inspection. Damaged capsules—those with dimples, blemishes, and other flaws—are pulled out before the capsules go to the bottling stage.

Photographs courtesy of Nature’s Way

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One morning late last winter, a wet snow fell over Salt Lake City and the surrounding mountains. The sky was ice-gray, and cars slipped off the highway with the drama of an Olympic skater on a bad night. It would be a good idea, one radio announcer advised, to stay indoors and whip up something good to eat.

Employees at two of the United States’ largest suppliers of herbal supplements were more or less doing that, only the result wasn’t a batch of cookies and a spoon to lick. Instead, these “chefs”, dressed in neatly pressed uniforms and wearing hairnets, plastic gloves, and face masks, were making as many as 60,000 echinacea, ginkgo, and other herbal capsules an hour, or up to 8.5 million little pills a day.

What is encapsulation?

The process of preparing plants and putting them into capsules is known as encapsulation. Capsules are tiny containers measuring less than an inch long and most often made of a clear, see-through gelatin. Capsules made of potato starch and turmeric or other non-animal ingredients also are used but are in less demand.

Herbal supplement makers produce huge numbers of capsules now, but encapsulation is fairly new to the trade. While the pharmaceutical industry has been making capsules for decades, the herb trade has only been at it full force since the 1980s, says Grace Lyn Rich, marketing director for Nature’s Herbs, an herbal supplement supplier to health-food stores based just south of Salt Lake in American Fork.

“We weren’t encapsulating in the 1960s, perhaps because capsules seemed too pharmaceutical or druglike and those who liked herbs wanted to be very separate from that,” Rich says. “By the mid-1970s, the herb trade was still considered ‘on the fringe’, but we were growing. By that time, most people didn’t want to fill their own capsules or concoct their own teas and were looking for an alternative to taking herbs by the spoonful. So we looked at how we could provide easier ways to use herbs.”

Taking a cue from the pharmaceutical industry, her company and others began purchasing encapsulation machines, primarily manual ones that could produce 100 capsules an hour. By the late 1970s, semiautomatic machines were added, speeding up production to 20,000 capsules an hour. By the 1980s, some herbal supplement makers had acquired automatic encapsulators, which can produce up to 60,000 capsules every hour.

One big kitchen

Like cooks, each herbal supplement maker has a particular way of doing things and chooses its own ingredients, processes, and tools. Manufacturers freely discuss many of their techniques; others are trade secrets. But some basic generalizations can be made about the process of getting a plant into a capsule.

As with any recipe, the starting point for making herbal capsules is assembling the ingredients. Supplement makers purchase herbs from growers and vendors all over the world. Some herbs grow only in specific regions, and sometimes the manufacturers get better quality or price outside the United States. Take dandelion for instance, a herb that has been used in traditional medicine to treat indigestion and a host of other ills. “You can’t buy and use dandelion grown in the United States because there isn’t one that hasn’t been sprayed with a weed killer,” says Neil Reay, marketing director for Nature’s Way, another major supplier of herbal supplements to retail stores and located in Springville, Utah. “But in Europe, dandelions are treated as a food, so we can get a much cleaner product there.”

This company and others keep close watch on their vendors and growers by conducting inspections, checking soil and climate conditions, which impact an herb’s potency, investigating whether the vendor or grower has been linked to “counterfeit” herbs, those that may look very similar to a desired plant and are substituted because they are cheaper, and watching the harvest to ensure that herbs are carefully handled and that organically grown crops aren’t being sprayed with pesticides. Product quality is the life­blood of the business, says Rich of Nature’s Herbs. “What is inherent in the plant is all you have,” she says. “You can make it worse but you can’t create quality. All you can do is preserve it.”

When the ingredients for herbal supplements have been selected, they are shipped to the manufacturer’s warehouse. Some supplement makers purchase whole herbs and grind them into powders at their factories; others purchase herbs that have already been powdered at other facilities, a variation that is basically a matter of manufacturer preference. Both whole and powdered herbs are shipped in sealed ­containers or 50-gallon drums to a warehouse where the air is thick with the earthy smell of herbal medicine—sometimes the only indication that the manufacturing facility is an herbal one. Plants or even plant parts are nowhere to be seen (except in the on-site laboratories) because of carefully controlled warehouse environments designed to protect herbs from contamination from pollutants and from each other. It wouldn’t do, for example, to have ephedra mingling with echinacea when the manufacturer is making and labeling a product as containing only echinacea.

When herbs arrive at the warehouse, they are quarantined until botanists, chemists, microbiologists, and other scientists from the company’s laboratories test each shipment to ensure that the herbs are what they are supposed to be and to monitor for purity, potency, and problems such as mildew. At the Solaray laboratories in Ogden, Utah, director Brent Roth and his staff of thirty begin an arsenal of testing with the obvious: taste, touch, and smell. Microscopy primarily determines what an herb isn’t; positive identification and evaluation of potency are arrived at by thin-layer chromatography and high-pressure liquid chromatography. Once the product has passed these tests, it is given a company identification or lot number and officially logged into the manufacturer’s computerized tracking system.

The tracking system holds a lot of information about an herb, including where it was grown and who has touched it along its way to and inside the manufacturing facility. The manufacturer can trace the product literally back to its roots if problems with the product arise or if the company or government agencies want more information about the herb shipment.

After the herbs have been logged into the computer, they are stored on warehouse shelves that might stand as high as four-story buildings. Employees order up the ingredients when they’re ready to make a batch of herbal capsules, which may range in size from 100 to 600 gallons, depending on the formula and consumer demand for the product.

In some facilities, it takes a computerized forklift to find the correct drums and pull them off the shelves. From there, the herbs go through a variety of procedures, including another manual inspection to check for problems such as sun damage, mold, and disease. The inspection also serves to ferret out foreign objects from the herb bales; Reay of Nature’s Way says it isn’t unusual for workers to find rocks, coins, nails, and even watches and knives mixed in with the herbs. Using magnets helps employees find and remove foreign objects; if a bale is diseased or otherwise damaged, they remove it from production.

Supplement makers who purchase whole rather than powdered herbs must grind plants before they can be encapsulated. That means milling herbs into fine powders. Sometimes huge crushing machines—one called “Jaws” at Nature’s Way—are used to break up herb bark and roots; this creates a coarse powder, which is further refined with other milling machines to a particle size resembling sawdust, and finally into a grit-free face-powder texture.

Once powdered, the herbs are mixed and blended according to the formula in huge stainless-steel mixers with arms to hold the drums. Depending on the herbs, fillers such as lactose are blended in to correct a gummy consistency or other condition unsuitable to a capsule. At Nature’s Herbs, herbal fillers are used. In the trade, fillers are known as manufacturing flow agents and don’t have to be identified on the supplement label. Other ingredients such as rosemary, a natural antioxidant that helps prolong shelf life without using chemical preservatives, may also be added.

Plants into pills

The capsule-making process is very noisy, sounding like the din from a giant vacuum cleaner. You have to almost shout to be heard above it.

Each encapsulating machine is kept in a separate room to keep herbal recipes from mixing. One piece of the encapsulating machine is a funnel into which the powdered herb is poured. During the process, gold, green or red powder, the color depending on the herb being used, piles up around the funnel and layers itself into every crevice of the machine. Some of it goes onto the floor. Herb powder is everywhere, although suction tubes are positioned close to the machines to catch dust and the air looks clear. Powder that falls onto the machines is swept up and reused because the machines are sanitized and scrubbed after every run. Any that falls on the floor is considered contaminated and unusable.

Near the funnel is a piece that looks a little like a waffle iron. It pulls empty capsules apart, squirreling away the lids and setting the bottom halves onto a circular steel wheel. The wheel and funnel work in rapid-fire tandem: the wheel whisks each half-capsule over to the funnel tip, then rests for the blink of an eye, enough time for the funnel to pump a precisely measured amount of herbal powder into the capsule. A smaller wheel somewhere inside the funnel tamps the herb material tightly into the capsule bottom, and the wheel turns quickly again, escorting the filled half-capsule back to its starting point. There, the machine retrieves the capsule’s lid and tamps it back on. The completed capsule is rushed out of the way to a moving ramp that spills the capsule into a barrel. All of this happens fast enough for the machine to produce 1,000 capsules in one minute. One worker supervises the machine, constantly checking herb and capsule flow and, every twenty minutes or so, weighing capsules to ensure that the promised dose has gone into the pills. Inspectors come around at various times to check the weight records.

Once the capsules have been made, they are taken out of the encapsulation room, rolled onto a conveyor belt, and scrutinized by workers wearing gloves and hairnets. The workers watch the capsules roll by, checking for blemishes, folds, splits, cuts, dimples, fibers, and hairs and pulling all damaged and contaminated capsules out. Capsules that make it through this inspection go to another machine, which polishes them to eliminate dust and make them publicly presentable. They go through another round of inspection before being packed into bottles.

160 a minute

Bottling the capsules is the final step. Machines count out capsules and drop them into empty bottles standing like soldiers at attention on another conveyor belt. The bottles then move beneath a laser, which seals a protective liner over the bottles’ tops. Another machine screws on a lid and another pastes on a label. Finally, a machine shrink-wraps plastic over the entire bottle, and an herbal supplement is born—160 bottles of them every minute. This full-bottle seal assures the consumer that the product wasn’t tampered with after it leaves the manufacturer and makes its way to store shelves.

Medicine of the future

Capsules are a link to the tradition of using herbs in whole forms to get as many of the herbs’ constituents as possible and to gain the synergistic effect of those constituents working together. They have helped make the herbal supplement business a big one—in Utah alone, Reay says, the herb industry contributes $2 billion to the state’s economy. But capsules are only one part of the picture of the future herb industry. Supplement makers foresee more sophisticated ways to standardize herbal ingredients as they continue to learn more about herbs and how to extract their essence.

“Singles—single herbs in capsule form, like echinacea—are our biggest-selling segment,” Rich says. “But ten years from now, extracts will be the bigger product because the interest will be in what we can duplicate, and people just want the ease of having a product that is specific to their needs. Extracts and their ability to be duplicated provide that. Singles will always be there, though. It’s who we are and where we came from.”

Jan Knight is editor of Herbs for Health.