Lesson 2: Dose levels

Therapeutic dose range

Each herb has a recommended therapeutic dose range, within which a suitable dose for most adults will be found.

Minimum therapeutic dose
This is the smallest dose that will have a therapeutic result. Below this is the sub-therapeutic dose, which is too small to have a therapeutic effect.

Maximum dose
In the case of herbs with potential adverse effects, this is the largest dose that is safe to administer.
The toxic dose is the dose, at and above which adverse reactions due to toxic effects are likely to occur.

In the case of herbs like Althaea, for which there are no reports of adverse effects even at overdose levels (M&B Safety), the maximum dose can be defined as the largest dose that is generally necessary to obtain a therapeutic effect.

Differences of opinion

The statement on dose above sounds clear and definite. The problem is that there are often differences of opinion as to what constitutes the minimum and maximum therapeutic dose for a specific herb, and even for the same herb when treating different disorders.

Amongst herbal practitioners world-wide there exist what have been called the higher dose approach and the lower dose approach. This topic is discussed in PPMM and in B&M.

I generally take a middle road between the two approaches, and modify my dosages depending on the needs of the patient, and on new research data as it becomes available for a specific herb.

Common sense dosing 
Different patients have different dose requirements, and for a particular patient, dose requirements may vary with time and circumstances.

• Here are some commonsense guidelines for dose:
• Use the least dose required to get the desired therapeutic effect.
• Use higher doses, short-term, for acute conditions, and lower doses, long-term, for chronic conditions.
• In chronic cases, start at the minimum therapeutic dose for 1 to 3 days, so that the patient’s body can become accustomed to the herbs, then increase the dose, up to the maximum therapeutic dose if necessary, to get the optimal therapeutic effect.
• Use the herbs for the minimum time before reducing the dose: this may be 3 to 5 days in an acute situation, or 2 to 4 weeks in a chronic situation; if this reduction still produces the same therapeutic effect, keep the reduced dose, if not, return to the original dose.
• Increase the dose if symptoms return, or modify the herb combination, or change to a different combination.
• Vary the dose to meet the changing requirements of the patient.

Sources

In chronological order, the publications used as sources for this database for dose are: BHP, BHC1, BHC2, ESCOP, M&B Safety, and B&M. In addition, the dose for some herbs has been influenced by online publication of clinical research on PubMed. When a dose listed is my opinion, from my clinical experience, it is marked JR.

A general guide

Average herbs
Very approximately, the dose for the average herb, given in this database, is 0.5-2 g of dried herb or 1-3 ml of 1:3 tincture, three times per day, for an adult.

Strong herbs
However, some herbs are more potent, and their doses may be much less. For example, the maximum permitted dose in the UK of Lobelia inflata is 0.2 g of dried herb or 1 ml of 1:5 tincture, three times per day.

Acute and chronic doses
Acute conditions may need higher doses, for example, for acute influenza with fever, the dose of dried Achillea, as a warm infusion, is 6 g, maybe 6 times per day. But for a chronic condition, 3 g, three times per day is usually enough.

Examples
Some examples are shown in the Table below.

Single herb or herb combination
When a herb is prescribed as a single herb, it has to do all the work, and the dose is higher. When a herb is part of a multi herb combination, it is acting as part of a team of herbs, and the dose of the herb is less than when prescribed singly.
For example, if Lavandula were used for severe insomnia, the individual dose of dried herb might be 4 g. But if Lavandula were combined with equal amounts of Humulus, Melissa, and Valeriana for this problem, the amount of each individual herb might be 1 g.

Dose forms
Dose varies with dose form, and the preferred dose form varies with the herb and the situation: see Table in the Dose and Forms section of this lesson.

Herb examples:
Achillea  best as infusion, especially for acute conditions
Althaea  best as decoction
Crataegus  best, and most convenient as 1:2 or 1:1 liquid extract (1:3 tincture is too weak), or as pills or capsules of concentrated Crataegus extract.
Lavandula  maybe best as 1:3 tincture, since processing for liquid extracts may remove some of the aromatic oils