Guides
Buying and Storing Herbs Safely at Home
Herbal safety starts with getting the right plant species and keeping it in good condition. Loose herbs exposed to light, humidity and dust in open sacks lose active constituents and can harbour mould toxins (mycotoxins).
Updated: October 15, 2026
1. Common names are not enough: check the Latin name and plant part
Different plants often share the same common name. In Turkish, "kantaron" refers both to St John's wort (Hypericum perforatum), which interacts with many medicines, and to centaury (Centaurium erythraea).
Likewise, an assessment for one plant part (such as peppermint leaf) does not automatically apply to another (such as pure essential oil). Always check the Latin botanical name and the plant part (leaf, flower, root, seed) on the label.
2. Risks of unlabelled loose-bin herbs
Herbs kept in open bins absorb moisture from the air and collect dust. Damp plant material can grow moulds and harmful mycotoxins even before visible fuzz appears.
Aromatic herbs such as peppermint, chamomile, lemon balm and thyme quickly lose their volatile oils when left uncovered.
- Prefer sealed, light-protective packaging with a batch number and expiry date.
- Reject faded, clumped or musty-smelling plant material.
- Avoid unlabelled multi-herb "slimming teas" or pastes with undisclosed ingredients.
3. Storing herbs safely at home
Keep dried herbs away from heat and steam above the stove or in the bathroom. Store them in airtight dark glass jars or tins inside a cool, dry cupboard.
Do not store pre-ground oily seeds such as linseed or black seed for long periods; once crushed, their fixed oils oxidise and turn rancid quickly. Grind small amounts fresh before use.
4. Typical shelf life
Well-stored dried flowers and leaves are best used within about 1 year, and roots or barks within 1–2 years. Once opened, fixed and essential oils oxidise faster and should be kept tightly capped in dark bottles.
Frequently asked questions
Is it safe to buy loose herbs from open bins?
Open bins carry a higher risk of species mix-ups, dust and moisture-related mould. Sealed packages listing the Latin name and expiry date are safer.
Should dried herbs be kept in the fridge?
No. Dried herbs can absorb condensation in the fridge; keep them in an airtight jar in a cool, dry cupboard. Cold-pressed oils such as linseed oil, however, should be refrigerated after opening.
How can I tell if dried herbs have gone bad?
Discard herbs that have lost their aroma and colour, smell musty or rancid, or show any sign of dampness or insects.
Sources
- Patient leaflet template concerning advice on the preparation of herbal teas as (traditional) herbal medicinal products by end-usersEMA HMPC · 2016
- WHO Monographs on Selected Medicinal Plants (Volumes 1–4)World Health Organization · 2009
- Trease and Evans Pharmacognosy (16th Edition)Elsevier Health Sciences · 2009
Related herbs
Sage
T Traditional useSalvia officinalis
Sage leaf is traditionally used as a gargle for mouth and throat inflammation, for mild indigestion and for excessive sweating.
Chamomile
T Traditional useMatricaria recutita
A gentle herbal tea traditionally used for bloating and mild stomach cramps, common cold symptoms and mouth or throat irritation.
St. John's Wort
A Strong clinical evidenceHypericum perforatum
St John's wort extract may help with mild to moderate depressive episodes, but it seriously interacts with many medicines, including the pill.
Senna
A Strong clinical evidenceSenna alexandrina
A stimulant laxative for short-term relief of occasional constipation. No longer than 1 week; not for children under 12, in pregnancy or while breastfeeding.