Research Library · Plants & herbs · Video research · Mind & nervous system
🍋 Lemon balm project — every summary and video → 🌿 Sajah Popham project — every summary and video →Lemon balm and the overactive thyroid
Sajah Popham's “happiest herb on Earth” for a racing heart, a restless mind and an overactive thyroid — checked against the laboratory work, the clinical trials, the old herbals and the sky Culpeper gave it.
15 October 2026 16 min read ▶ 40-min video 52 sources · 37 peer-reviewed
In brief
Herbalist Sajah Popham calls lemon balm the happiest herb on Earth and picks it for the overactive thyroid: it cools, calms the nerves and the racing heart, and — he says — acts on the thyroid itself. The calming is real in small trials, and one trial found fewer palpitations. The thyroid action is real too, but only in test tubes and rats in the 1980s: extracts kept the thyroid's stimulating signal, and the antibodies of Graves' disease, off their receptor. No trial has given lemon balm alone to people with an overactive thyroid, so it belongs beside medical care, not instead of it. Its traditional dose is a tea of 1.5–4.5 g of leaf; the EU monograph doesn't advise it under 12, for lack of data.
Learn from the source
Sajah Popham
Herbalist and host of The Plant Path; founder of the School of Evolutionary Herbalism.
He teaches herbal medicine through the energetics of plants and people, and herbal astrology alongside it.
evolutionaryherbalism.com ↗ Every summary of Sajah Popham’s work →
Heat, speed and a runaway signal
The overactive thyroid
The thyroid sets the body's pace — Popham compares it to an engine's idling speed. The brain controls it through a chain: the hypothalamus signals the pituitary, the pituitary releases thyroid-stimulating hormone (TSH), and the thyroid answers with T4, which the body's tissues turn into T3, the active form. When T4 and T3 run high the brain turns TSH down, so an overactive thyroid shows on a blood test as low TSH with high T4 and T3 — just as he explains.
For members
Read the whole summary
10 sections, 5 diagrams, the video with its chapters, 23 claims checked against the research, 52 sources with the names of the people who did the work and links to it — and downloads in PDF, Word, Excel and PowerPoint.
- 🔒 Does lemon balm act on the thyroid?
- 🔒 Bugleweed, lemon balm and motherwort
- 🔒 Calm, sleep and the heart
- 🔒 For children, and in the cup
- 🔒 An antiviral? Cold sores, mostly
- 🔒 Beyond the herbs
- 🔒 Lemon balm in medical astrology
- 🔒 Two thousand years of balm
- 🔒 What the research says
The Research Library is part of every paid plan: Crescent, Half Moon and Full Moon.
More in these projects
This is the first summary in the project — more are on the way.
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- Hawthorn, the heart herb ▶ 9-min video · Herbalist Sajah Popham's Sun-ruled tonic for the heart, the blood vessels and an anxious mind — checked against the small trials, the…
- Angelica, the warming bitter ▶ 9-min video · Herbalist Sajah Popham's Sun-ruled herb of warmth, for cold digestion, cold hands and a cold uterus — checked against the herbal…
- Ashwagandha, the calm adaptogen ▶ 6-min video · Herbalist Sajah Popham's Sun-ruled herb of vitality, for stress, sleep and the immune system — checked against the trials, the…
- St John's wort, the midsummer flower ▶ 10-min video · Herbalist Sajah Popham's Sun-ruled herb of the spirit, for low mood, the liver and nerve pain — checked against the depression trials,…
- Judith Hill: time matters ▶ 93-min video · Medical astrologer Judith Hill, interviewed by her student Sajah Popham: timing herbal medicine by the Moon, the zodiac in the body, the…
- Burdock, the all-purpose alterative ▶ 13-min video · Herbalist Sajah Popham's gentle blood cleanser for the liver, the lymph, the skin and the gut — checked against the chemistry of inulin,…
- Dandelion leaf, the potassium diuretic ▶ 8-min video · Herbalist Sajah Popham's “universal diuretic” that brings its own potassium — checked against the one study in people, the food tables,…
- Nettle, the mineral powerhouse ▶ 11-min video · Herbalist Sajah Popham's spring tonic for the blood, the kidneys, the skin and hay fever — checked against the food tables, the…