Dosing and Safety
Part of Herbal Medicine
“The dose makes the poison” — this principle applies to every medicinal plant. Even safe herbs cause harm in excess, and many effective medicines are separated from dangerous poisons by a thin margin. Understanding dosage calculation, contraindications, and safety protocols is what separates healing from harm.
The Fundamental Principle
Every medicinal plant contains active chemical compounds. These compounds have a therapeutic range — below this range, they are ineffective; above it, they cause adverse effects or toxicity. The goal of dosing is to stay within the therapeutic range.
Therapeutic Index
| Category | Examples | Margin of Safety |
|---|---|---|
| Very safe (wide margin) | Chamomile, peppermint, elderberry | 10-50x therapeutic dose before harm |
| Moderately safe | Valerian, echinacea, St. John’s wort | 3-10x therapeutic dose |
| Narrow margin | Foxglove (digitalis), comfrey (internal) | 1.5-3x therapeutic dose |
| Dangerous | Belladonna, monkshood, hemlock | Therapeutic dose is near lethal dose |
Never use narrow-margin or dangerous plants without extensive knowledge and experience. A rebuilding community should stick to well-documented, wide-margin herbs for all routine medical care. The plants listed as "dangerous" above are included for awareness, not as an invitation to experiment.
Standard Adult Dosing
By Preparation Type
| Preparation | Standard Adult Dose | Frequency | Notes |
|---|---|---|---|
| Dried herb tea (infusion) | 1-2 tsp per cup | 3x daily | Steeping time affects strength |
| Strong infusion | 30 g per liter | 1-3 cups daily | Medicinal strength |
| Decoction (roots/bark) | 15-30 g per 500 ml | 1-3 cups daily | Simmer 20-40 min |
| Tincture (standard) | 1-5 ml | 3x daily | Highly variable by herb |
| Syrup | 5-10 ml | 3-4x daily | Cough/throat remedies |
| Salve/ointment | Thin layer | 2-3x daily | External only |
| Poultice | As needed | Change every 2-4 hours | External only |
Duration Guidelines
- Acute conditions (cold, flu, wound): use intensively for 7-10 days, then stop
- Chronic conditions (joint pain, anxiety): use for 4-6 weeks, then take a 1-week break
- Tonic herbs (gentle nutritive herbs): safe for months of continuous use
- Strong herbs: do not exceed 2-3 weeks without a break
The "5-day rule" is a useful safety guideline: if an herbal remedy has not shown any improvement after 5 days of proper dosing, it is either the wrong remedy, the wrong dose, or the condition requires different intervention. Reassess rather than simply increasing the dose.
Adjusting Doses for Different People
Children’s Doses
Children are not small adults — they metabolize drugs differently and are more sensitive. Several historical rules approximate pediatric dosing:
Young’s Rule (by age): Child’s dose = (Age / (Age + 12)) x Adult dose
Clark’s Rule (by weight): Child’s dose = (Child’s weight in kg / 70) x Adult dose
| Age | Young’s Rule | Approximate Fraction |
|---|---|---|
| 1 year | 1/13 of adult dose | ~8% |
| 2 years | 1/7 | ~14% |
| 4 years | 1/4 | 25% |
| 8 years | 2/5 | 40% |
| 12 years | 1/2 | 50% |
| 16 years | 2/3 | 67% |
For children under 2 years, limit herbal medicines to the mildest herbs only: chamomile, fennel, and weak peppermint tea. Even these should be given in small quantities (30-60 ml at a time). For serious illness in infants, herbal medicine should supplement, not replace, all other available care.
Elderly Doses
Start at one-half to two-thirds of the standard adult dose for people over 65. Metabolism slows with age, and sensitivity to active compounds often increases. Increase gradually if needed.
Pregnancy Considerations
Many herbs that are safe for the general population are dangerous during pregnancy. The following categories should be strictly avoided during pregnancy:
- Uterine stimulants: pennyroyal, blue cohosh, tansy, mugwort, rue
- Strong laxatives: senna, cascara, aloe (internal)
- Hormonal herbs: vitex, dong quai, black cohosh (first trimester)
- High-alkaloid herbs: goldenseal, barberry (berberine-containing plants)
Generally safe during pregnancy (in normal food/tea amounts): ginger (for nausea), peppermint, chamomile, raspberry leaf (third trimester only), and lemon balm.
When in doubt, do not use herbal medicine during pregnancy unless the benefit clearly outweighs the risk.
Identifying Adverse Reactions
Allergic Reactions
Watch for these signs within 30 minutes to 2 hours of first use:
- Skin rash, hives, or itching
- Swelling of lips, tongue, or throat
- Difficulty breathing
- Nausea or vomiting
Action: Stop the herb immediately. If swelling affects breathing, this is a medical emergency.
Dose-Related Side Effects
| Symptom | Likely Cause | Action |
|---|---|---|
| Nausea, stomach upset | Dose too high or empty stomach | Reduce dose, take with food |
| Diarrhea | Herb is laxative (senna, cascara) or dose too high | Reduce dose |
| Headache | Detoxification effect or sensitivity | Reduce dose, increase water intake |
| Drowsiness | Sedative herb (valerian, hops) at too high a dose | Reduce dose, avoid dangerous activities |
| Skin sensitivity to sunlight | Photosensitizing herb (St. John’s wort, angelica) | Avoid sun exposure while using |
| Racing heart | Stimulant herb (ephedra, ma huang) | Stop immediately |
The Test Dose Protocol
For any herb you have not used before:
- Day 1: Take one-quarter of the standard dose
- Wait 24 hours — observe for any adverse reaction
- Day 2: If no reaction, take one-half dose
- Day 3: If no reaction, take the full dose
- Continue at the full dose if well-tolerated
This three-day ramp-up catches both immediate allergic reactions and delayed sensitivities.
Herb-Herb Interactions
Some herbs interact with each other, amplifying or canceling effects.
Combinations to Avoid
| Herb A | Herb B | Interaction |
|---|---|---|
| St. John’s wort | Any herb metabolized by the liver | St. John’s wort speeds liver metabolism, reducing the effectiveness of other herbs |
| Valerian | Other sedative herbs (hops, passionflower) | Combined sedation may be excessive |
| Licorice root | Blood pressure-raising herbs | Licorice raises blood pressure; combination can be dangerous |
| Blood-thinning herbs (willow bark, meadowsweet) | Other blood thinners | Risk of excessive bleeding |
| Stimulant herbs (ephedra, guarana) | Heart-affecting herbs | Heart rate and rhythm disturbances |
Beneficial Combinations
| Combination | Purpose | Why It Works |
|---|---|---|
| Chamomile + peppermint | Digestive upset | Complementary mechanisms |
| Elderberry + echinacea | Immune support | Different immune pathways |
| Willow bark + meadowsweet | Pain relief | Similar but gentler than either alone |
| Ginger + peppermint | Nausea | Ginger reduces nausea; peppermint calms stomach |
| Valerian + lemon balm | Insomnia | Gentle combined sedation |
Toxicity Recognition and Response
Signs of Plant Poisoning
In order of severity:
- Mild: Nausea, vomiting, diarrhea, stomach cramps, excessive salivation
- Moderate: Dizziness, confusion, blurred vision, excessive sweating, rapid or slow heartbeat
- Severe: Seizures, loss of consciousness, difficulty breathing, cardiac arrhythmia
- Critical: Respiratory failure, cardiac arrest
Emergency Response
- Stop administration of the herb immediately
- Identify the plant if possible — save a sample for reference
- If the person is conscious and alert: induce vomiting ONLY if ingestion was within the last 30 minutes and the person is fully conscious. Use: finger at back of throat, or saltwater (2 tablespoons in a glass of warm water).
- Activated charcoal — if available, administer 25-50 g in water. Charcoal binds many toxins in the gut.
- Keep the person calm, warm, and lying on their side (recovery position) in case of vomiting
- Monitor breathing and pulse continuously
Do NOT induce vomiting if the person is drowsy, unconscious, or having seizures — aspiration risk is deadly. In these cases, place in recovery position and focus on maintaining an open airway.
Record Keeping
In a community without printed references, maintaining local knowledge is critical.
What to Record
For each herb used medicinally, maintain a written record of:
- Plant identification — detailed description, drawing, habitat
- Preparation method — exact procedure used
- Dose given — amount, frequency, duration
- Patient response — improvement, side effects, time to effect
- Outcome — resolved, partially helped, no effect, adverse reaction
Building a Community Formulary
Over time, these records become your community’s pharmacopoeia — the accumulated knowledge of which plants work, at what doses, for which conditions. This is invaluable knowledge that must be preserved and passed down.
Common Mistakes
- “More is better” thinking — doubling the dose does not double the effect. It often produces side effects without additional benefit. Respect the therapeutic range.
- Assuming “natural” means “safe” — hemlock, belladonna, and foxglove are all natural. So is arsenic. Natural does not equal harmless.
- Not adjusting for body size — a 50 kg person and a 100 kg person should not take the same dose. Use weight-based calculations.
- Ignoring pregnancy — many common herbs are uterine stimulants. Always check before giving any herbal medicine to pregnant women.
- No test dose for new herbs — allergic reactions are unpredictable. Always start low and ramp up over three days.
Summary
Dosing and Safety — At a Glance
- Every herb has a therapeutic range — stay within it. More is not better.
- Standard adult tea dose: 1-2 tsp dried herb per cup, 3x daily; tinctures: 1-5 ml, 3x daily
- Adjust for children (Young’s Rule: age/(age+12) x adult dose) and elderly (start at half dose)
- Avoid uterine stimulants, strong laxatives, and high-alkaloid herbs during pregnancy
- Use the 3-day test dose protocol for any herb used for the first time
- If no improvement after 5 days, reassess — do not simply increase the dose
- For suspected poisoning: stop the herb, identify the plant, consider activated charcoal, maintain airway
- Keep written records of every treatment — doses, responses, outcomes — to build community knowledge