Short answer

We found no documented interaction between Boron and L-theanine in the sources below. That isn't proof the combination is right for you: check each one's cautions, and ask your pharmacist if you take medication.

Boron

What it is: A trace mineral found in many foods. It isn't considered essential because no clear role in the body has been identified.

What the research says: It may play a part in bone health, calcium use and steroid hormones, but this isn't proven.

Cautions

• Adults shouldn't exceed 20 mg a day.
• Most boron poisonings come from swallowing boric acid or borax products, not food or supplements.

Medicines to check

• No clinically relevant medicine interactions are known

In Holitro: Boron (10 mg per capsule)

Source: NIH Office of Dietary Supplements: Boron: Fact Sheet for Health Professionals (updated June 2022)

L-theanine

What it is: An amino acid found in green tea, taken for calm and sleep.

What the research says: Small studies suggest it may improve sleep; results for anxiety are mixed.

Cautions

• No side effects have been reported for the supplement.
• It may not be safe in pregnancy or while breastfeeding.

Medicines to check

• Sleep medicines and sedatives (such as lorazepam, diazepam or zolpidem): may add to drowsiness

In Holitro: Theanine 200mg (200 mg per capsule)

Source: Memorial Sloan Kettering Cancer Center, About Herbs: L-Theanine (updated July 2026)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.