Herbal Capsules, Tablets and Powders
What herbal capsules, tablets and powders are, what a 2025 lab study found about their contents and breakdown, and why a tea study does not apply to a capsule.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
The question: are herbal capsules, tablets and powders the same as the tea?
No. They are solid forms, and a result for the plant as a tea does not transfer to them. A capsule may hold ground plant, or a concentrated extract, or both. The label should tell you which. This page explains the forms and what the evidence says about product quality. It gives no amounts.
Two warnings come first. NCCIH reports that liver injury, although uncommon, has been reported with green tea products "primarily" in tablet or capsule extract form. [1] And the US FDA has found prescription drugs in some products sold as dietary supplements, so "what's on the label may not be what's in the product". [2] NCCIH lists liver damage symptoms as fatigue, nausea, poor appetite, dark urine or jaundice. If you notice them while using a supplement, talk with a health care provider. [3] See liver safety and supplements.
The forms
NCCIH lists supplements as "teas, extracts, tablets, capsules, powders, or in other forms". [2]
| Form | What the regulator or source says | Notes |
|---|---|---|
| Powder | EMA lists "comminuted or powdered herbal substances" among herbal preparations. [4] The valerian monograph also lists a powdered herbal substance. [5] | Powdered whole plant is different from a concentrated extract. |
| Capsule | A solid dosage form for swallowing; the study below compared gelatin and cellulose-based shells. | Shell type is covered below. |
| Tablet or caplet | A solid dosage form for swallowing. | Check the "other ingredients" list on the label; see reading supplement labels. |
| Extract in a solid form | Dry extracts appear throughout the EU monograph for valerian, with listed extraction solvents. [5] | See standardized extracts. |
The plant part and scientific name matter as much as the form. EMA says herbal substances are defined by "the plant part used and the botanical name". [6] See botanical names and plant parts on labels.
What research shows about the quality of solid forms
Most evidence here is about product quality, not health outcomes.
| Question | What the source found | Strength of evidence |
|---|---|---|
| Do capsules and tablets contain the marker compounds expected? | A 2025 study tested 73 oral products containing Lavandula (lavender) species. It found that 63% "contain less or none of the main marker compounds". Some contained rapeseed and sunflower oils as excipients, sometimes undeclared. [7] | One laboratory study of one plant; product-specific. The authors disclosed that one author's position was funded by a donation from a manufacturer. |
| Do solid forms break down as expected? | In the same study, 30% of oral solid formulations "always failed the disintegration testing". Gelatin capsules had higher pass rates than cellulose-based capsules. [7] | Same study; it does not show effect on health. |
| Does the label match the contents? | NCCIH reports some milk thistle products had silymarin amounts "substantially different" from the label. [8] | Official summary of product testing. |
| Is a capsule better or worse than a tea for a health outcome? | Proper evidence not found. We read NCCIH, EMA and PubMed sources and found no direct human comparison. | Not applicable |
| Are powders safer or more effective than capsules? | Proper evidence not found. No source we read compares them. | Not applicable |
The lavender study is about oral lavender products, not the essential oil; for that see Essential Oils & Aromatherapy. We cannot say how far its results extend to other plants.
Frequently asked questions
Is a capsule stronger than a tea?
The sources we read do not say. They are different products with different contents. A regulator notes that different herbal preparations may act differently. [9]
Do herbal capsules always contain what the label says?
Not always. NCCIH says the label may not match the contents. [2] In the lavender study, 63% of products had less or none of the main marker compounds. [7]
Is a powder the same as the whole plant?
A powdered herbal substance is the ground plant material, as EMA describes it. [4] A concentrated extract in powder form is different. Check the label.
Why does capsule shell type matter?
In one laboratory study, gelatin capsules passed a breakdown test more often than cellulose-based ones. [7] We do not know what this means for health effects.
Can I open a capsule and make a tea?
Do not. A capsule is a different product from the tea, and its contents may differ from the plant. Ask a pharmacist.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety by group
- Medicines: herbs in any form can interact with medicines. Link: medication interactions. Ask a pharmacist.
- Surgery: tell the surgical team about every supplement. NCCIH notes certain supplements "may increase the risk of bleeding or affect your response to anesthesia". [2] See supplements before surgery.
- Pregnancy, breastfeeding, children, older adults: see pregnancy and breastfeeding and children and teens.
- Quality and contamination: see product quality and contamination and quality testing and certifications.
References
- NCCIH (US). Green Tea. Read 2026-10-23.
- NCCIH (US). Using Dietary Supplements Wisely. Read 2026-10-23.
- NCCIH (US). Turmeric. Read 2026-10-23.
- European Medicines Agency. Herbal preparations (glossary). Read 2026-10-23.
- European Medicines Agency, HMPC. European Union herbal monograph on Valeriana officinalis L., radix, EMA/HMPC/150848/2015, 2016. Read 2026-10-23.
- European Medicines Agency. Herbal substances (glossary). Read 2026-10-23.
- Jalil B, Heinrich M. Pharmaceutical quality of herbal medicinal products and dietary supplements: a case study with oral solid formulations containing Lavandula species. Eur J Pharm Sci 2025. PMID 39952369. Read 2026-10-23.
- NCCIH (US). Milk Thistle. Read 2026-10-23.
- European Medicines Agency, Committee on Herbal Medicinal Products. Glossary on herbal teas, EMA/HMPC/5829/2010 Rev.1, 2010. Read 2026-10-23.