Reference : Herbs to Avoid or Use Caution During Pregnancy

Many herbs contain steroids that can affect the baby's development during pregnancy and/or nursing. Others may be of a mild toxic type, and others may be strong uterine stimulants. Please read this section carefully and take heed.

Angelica - stimulates suppressed menstruation
Black Cohosh - uterine stimulant - mostly used during labor
Blue Cohosh - a stronger uterine stimulant
Borage oil - a uterine stimulant - use only during the last few days of pregnancy
Comfrey - can cause liver problems in mother and fetus - use only briefly, externally only, for treating sprains and strains -
Dong Quai - may stimulate bleeding
Elder - do not use during pregnancy or lactation
Fenugreek - uterine relaxant
Goldenseal - too powerful an antibiotic for the developing fetus, also should not be used if nursing
Henbane - highly toxic
Horsetail - too high in silica for the developing fetus
Licorice Root - can create water retention and/or elevated blood pressure
Motherwort - stimulates suppressed menstruation
Mugwort - can be a uterine stimulant
Nutmeg - can cause miscarriage in large doses
Pennyroyal Leaf - stimulates uterine contractions (NOTE: Pennyroyal essential oil should not be used by pregnant women at any time!) - do not handle if pregnant or nursing
Rue - strong expellant
Saffron - can cause miscarriage and other problems
Shepherd's Purse - used only for hemmorhaging during/after childbirth
Uva Ursi - removes too much blood sugar during pregnancy and nursing
Yarrow - uterine stimulant

Calculating Capsule Dosage Amounts

Here's How:

1. Determine the capsule size you will need. Standard capsules are size "00" and measure about 5/8 in diameter. Smaller capsules are "0" larger capsules are size "000".
2. 2 "00" sized capsules will hold 1 teaspoon or 1300 mg of dried herb. This equals 60 drops or 1 teas. of tincture.
3. 2 "0" sized capsules hold 3/4 teaspoon or 1000 mg of dried herb.
4. 2 "000" sized capsules hold approx. 1 1/3 teaspoon or 1600 mg of dried herb.
5. 1 oz. of dried herb will make approx. 60 "0" sized capsules and 30 "00" sized capsules.
6. For medicinal teas 1 oz herb for each pint of water. This is quite different than using tea bags.
7. For herb oils using fresh herb are 8 oz herb in 1 pint oil or 4 oz herb to 1 pint oil.
8. For size "00" capsules the standard dosage is 2, 3 times per day.
9. Be sure to check out the resources below for more information.
   

Tips:

1. These Instructions are for working with raw herb and do not apply to standardized products.
2. If making your own, don't forget to label container with the herb and dosage.
3. If you are unfamiliar with an herb, always start with a lower dosage.