L-theanine comparison: heavy-metal lab reports, purity and price per day (UK + EU)
2 L-theanine products; 2 are lab verified with an independent batch report we opened ourselves (1 UK seller, 1 EU seller).
Prices were checked on the seller pages on 22 Oct 2026 and the price per day is calculated at the label dose; € and £ are never mixed or converted.
Purity: Everyday Supplements’ report measured 101.65% L-theanine (200.26 mg per 200 mg capsule); Heiltropfen’s published reports have no purity result, only heavy metals and microbiology.
No purity (L-theanine content) result in the published lab reports.
The sample was supplied by the brand (sampler: client), not taken by the lab.
Heavy-metal colours:0.01 Well under the EU limit (below half) or below detection▲1.6 Near the EU limit (half the limit up to the limit)■3.2 Over the EU limit0.30 Grey: no EU limit (arsenic), not tested, or the lab’s reporting limit is above the EU limitEU 2023/915 limits for food supplements: lead (Pb) 3.0, cadmium (Cd) 1.0, mercury (Hg) 0.10 mg/kg. Values in mg/kg. NT = not tested; c = calculated by us from µg per serving.
Pb = lead, Cd = cadmium, Hg = mercury, As = arsenic, all in mg/kg. “<” means below the lab’s detection limit. Pass* = certificate states compliance without a figure. — = no data. Label match = the lab measured the active content against the label. The lab name, full notes and per-serving details are on each product page.
Pb<0.025 (well under the EU limit or below detection)Cd<0.022 (well under the EU limit or below detection)Hg<0.005 (well under the EU limit or below detection)As<0.010 (well under the EU limit or below detection)
Label match
Yes
Fillers
None
Form & serving
Capsules (vegan HPMC)
200 mg per capsule; label says 1–2 capsules a day
Price per daily dose
£0.37–£0.73/day(UK)
calculated: £32.99 ÷ 45–90 · 1–2 capsules a day · free UK standard delivery over £50
Pb<0.01 (well under the EU limit or below detection)Cd<0.003 (well under the EU limit or below detection)Hg<0.01 (well under the EU limit or below detection)As<0.01 (well under the EU limit or below detection)
Label match
Unknown
Fillers
None
Form & serving
Powder (unflavoured)
400 mg a day (one level 2.5 ml scoop)
Price per daily dose
€0.065/day(EU)
calculated: €16.32 ÷ 250 · 400 mg a day · price incl. VAT; can differ by delivery country
No purity (L-theanine content) result in the published lab reports.
The sample was supplied by the brand (sampler: client), not taken by the lab.
Heavy-metal colours:0.01 Well under the EU limit (below half) or below detection▲1.6 Near the EU limit (half the limit up to the limit)■3.2 Over the EU limit0.30 Grey: no EU limit (arsenic), not tested, or the lab’s reporting limit is above the EU limitEU 2023/915 limits for food supplements: lead (Pb) 3.0, cadmium (Cd) 1.0, mercury (Hg) 0.10 mg/kg. Values in mg/kg. NT = not tested; c = calculated by us from µg per serving.
EU 2023/915 limits for food supplements: lead 3.0, cadmium 1.0, mercury 0.10 mg/kg; there is no EU limit for arsenic in supplements. Both products measured all four metals below the lab’s detection or reporting limit. L-theanine has no authorised EU or UK health claim, so we make none. Prices can change; the Heiltropfen price includes VAT and can differ by delivery country.
Not medical advice. Testing status can’t be bought; seller links may be affiliate links (see disclosure). Disclosure
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About L-Theanine
What it is
An amino acid found naturally in tea leaves (Camellia sinensis).
Common forms
Capsules or unflavoured powder.
Typical label doses
Labels in our directory give 200–400 mg a day.
Note
Purity (the measured L-theanine content) is only known when the lab report includes it; heavy-metal reports alone do not show it.
There are no authorised EU or GB health claims for this ingredient, so we do not describe any benefits.
Information only, not medical advice. Food supplements are not intended to diagnose, treat, cure or prevent any disease. Speak to a healthcare professional before use, especially if pregnant or on medication.
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