HPMC stands for hydroxypropyl methylcellulose or simply hypromellose. HMPC is the material from which most supplement capsules are made. It is a clear, tasteless, suitable material for vegetarian and vegan food. It is usually made from wood pulp extraction.
Of course, many other materials can be made into supplement capsules. HPMC is by far the most common, but bovine gelatin capsules are still used occasionally, or there are more exotic options such as amylopectin made from tapioca extract.
Once upon a time, almost all vitamin capsules were made from bovine gelatin. As veganism and sustainability become more popular, the market trend is shifting away from gelatin capsules. Today, most supplement products in the UK and European markets are made from HPMC. Bovine gelatin tends to be used only in very low-cost products, or products that are not vegan insignificant, such as collagen capsules.
Are empty HPMC capsules natural?
Empty HPMC capsules themselves are made of wood and are therefore often described as natural. Of course, the contents of the capsules you buy may or may not be natural, but the shell itself is natural.
If empty HPMC capsules are already colored, the coating is likely synthetic. Titanium dioxide is commonly used to color capsules, and this synthetic colorant has some associated health risks and warnings. Capsules can be naturally colored, but only in certain colors. The green shade can be obtained with a chlorophyll coating, and the purple capsule shell can be obtained with purple carrot extract.