The Capsule Shell Nobody Talks About — and Why It Changes Everything

Most people do. The shell is invisible in the conversation about supplement quality — which is exactly why it is worth having.

The Four Main Capsule Types

• Gelatin — the industry default. Made from animal collagen, typically bovine or porcine. Cheap to produce. Sensitive to humidity and temperature, which affects both shelf life and dissolution rate. Prone to cross-linking, which can trap the contents and reduce absorption.
• Pullulan — a naturally fermented polysaccharide derived from tapioca. Fully plant-based, low oxygen permeability, and excellent moisture barrier properties. More expensive than gelatin, which is why most brands do not use it.
• Starch capsules — plant-derived but less stable than pullulan and HPMC. Prone to brittleness and inconsistent dissolution depending on humidity.
• HPMC (Hydroxypropyl Methylcellulose) — plant-derived cellulose. The clinical standard. The capsule type used in pharmaceutical-grade manufacturing and medical research trials. Every product in the Alchemy Fit range.

Why HPMC Is the Right Choice for Dry Powder Compounds

HPMC outperforms alternatives in several specific ways that matter for dry powder formulations:

• Moisture resistance — dry powders are hygroscopic; they absorb moisture, which degrades the compound and reduces potency. HPMC creates a reliable barrier that gelatin and starch capsules cannot match consistently.
• Temperature stability — gelatin shells soften and deform at elevated temperatures. HPMC maintains structural integrity across a wider range.
• Dissolution consistency — HPMC dissolves predictably in the digestive tract. An erratic dissolution rate means erratic release of the compound, which means inconsistent results.
• No cross-linking — gelatin capsules are prone to cross-linking when exposed to aldehydes, making the shell significantly harder to dissolve. HPMC does not cross-link. What you swallow is what you absorb.
• Inert composition — HPMC does not interact with the compounds it contains. It is chemically stable and non-reactive — the capsule of choice in pharmaceutical research where compound integrity is non-negotiable.

Why Most Brands Do Not Use HPMC

Cost. HPMC capsules are more expensive than gelatin. For a brand optimising for margin, the capsule shell is an easy place to cut without the customer ever knowing.

We made the choice once. We have not reconsidered it since. HPMC. Every product. Every batch. No exceptions.