In this article
What are herbal remedies?
Herbal remedies that are safe in moderation
Herbal remedies to avoid in pregnancy and use with caution in labour
Herbal remedies to avoid in pregnancy and in labour
What are herbal remedies?
Herbal remedies are produced from plants. They are sometimes called herbal supplements, herbal medicines, or medicinal herbs.
Herbal remedies come in many forms, for example, powders, tinctures, infusions, teas, capsules, or tablets. They're available over the counter from health-food shops and pharmacies.
Whether you're trying for a baby, or are pregnant, consult a qualified medical herbalist before taking any herbal remedies. If you do decide to take herbal remedies or drink herbal teas, tell your doctor or midwife.
Some herbal remedies are powerful and they work in the same way as prescribed medications. Just because they are natural products, it doesn't mean they are always safe, especially during pregnancy.
Don’t take herbal remedies at all if you are already taking prescribed medication. This also applies when you go into labour, as you may need certain drugs to help you give birth.
If you're giving birth by planned caesarean section, stop taking herbal remedies at least two weeks before the date of your operation. Many herbal remedies cause blood thinning, and this could lead to extra bleeding during your caesarean.
For the same reason, don't take herbal remedies if you develop any bleeding problems during pregnancy.
Essential oils used in aromatherapy are also classified as herbal remedies. Read more about using aromatherapy in pregnancy.
Herbal remedies that are safe in moderation
The following herbal remedies are safe to use in moderation in pregnancy, but should be used with caution.
Herbal remedy Reason for caution in pregnancy
Camomile, German (matricaria chamomilla) May cause irritation and allergic reactions when used as a cream on the skin. Excessive use may stimulate the nervous system and cause insomnia.
Chilli (capsicum frutescens) May cause diarrhoea if used in large quantities in cooking.
Echinacea (echinacea purpurea) Small doses are safe in pregnancy, but only use for up to seven days.
May cause nausea, abdominal pain, diarrhoea, allergic reactions, breathlessness, heartburn, constipation, mouth ulcers, headache, dizziness, insomnia and disorientation.
Eucalyptus Safe as a diluted essential oil in small doses, and can be added to steam inhalation to relieve sinuses.
Only use for short periods. Undiluted oil on your skin may cause irritation. Don't swallow the essential oil, as it may upset your stomach.
Ginger (zingiber officinale) Large amounts may cause blood thinning, so avoid if you have a history of miscarriage or have any vaginal bleeding during your pregnancy. Excessive amounts may cause abdominal discomfort, heartburn and itchiness. Don't have more than about three teaspoons of grated root ginger a day.
Stop taking ginger at least two weeks before any planned surgery, including a caesarean.
Lavender (lavandula angustifolia) Do not use if you are taking drugs for a heart condition, or antacid medication for heartburn. Can lower blood pressure, making you feel faint.
Peppermint (mentha piperita) May cause heartburn, nausea, vomiting and allergic reactions, including skin irritation, when the oil is used on skin. May be a heart stimulant.
Do not use if you are taking drugs for heart complaints or antacid medication for heartburn.
(Red) Raspberry leaf (rubus idaeus) Do not take before 32 weeks. May stimulate the womb (uterus), and cause miscarriage or premature labour. In large doses, it may lengthen your labour.
Do not use if you have previously had a caesarean, have placenta praevia, bleeding in late pregnancy, are expecting twins, or if you have anaemia or high blood pressure. Do not use if you are taking iron tablets. See Can raspberry leaf tea bring on labour?
Senna (senna alexandrina) Long-term, frequent use, or high doses, has been linked to laxative-dependence and liver toxicity.
Don't use if you have had a previous miscarriage or threatened premature labour. May cause abdominal pain and cramps, nausea and diarrhoea.
Safe if used only for short periods of time in pregnancy. Do not use when taking drugs that have an effect on the kidneys, including drugs to reduce fluid retention and regulate your heartbeat.
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Herbal remedies to avoid in pregnancy and use with caution in labour
You should not use the following in pregnancy, but you can use them in labour on the advice of a registered medical herbalist. Discuss any herbal remedies that you may wish to use in labour with your midwife or doctor in plenty of time before your due date.
Herbal remedy Reason to avoid in pregnancy and use with caution in labour
Cotton root (gossypium herbaceum) Stimulates the womb.
False unicorn root (chamaelirium luteum) Stimulates the womb in labour. Do not use if you are taking lithium.
Jasmine (jasminum grandiflorum) May cause contractions, miscarriage or premature labour in pregnancy, but may be used in labour.
Lady's mantle (alchemilla xanthoclora) Stimulates the womb. May cause liver toxicity in very large doses.
Squaw vine (mitchella repens) May over-stimulate the womb, cause miscarriage or premature labour.
Herbal remedies to avoid in pregnancy and in labour
Do not take the following herbal remedies in pregnancy or when you are in labour.
Herbal remedy Reason to avoid in pregnancy and labour
Alder buckthorn (rhamnus frangula) May cause cramp-like discomfort and nausea.
Long-term use may cause potassium deficiency, leading to heart problems and muscle weakness.
Aloe vera (aloe barbadensis) May cause birth defects and miscarriage. However, skin creams and gels that contain aloe vera are safe to use on your skin.
Angelica (angelica archangelica) May cause womb contractions.
Anise/aniseed (pimpinella anisum) May cause skin irritation.
Arbor vitae (thuja occidentalis) May cause vomiting, diarrhoea, asthma, seizures, miscarriage, or premature labour.
Autumn crocus (colchicum autumnale) May affect cell division and lead to birth defects.
Barberry (berberis vulgaris) May cause very strong contractions and fetal distress. Also causes low blood sugar.
Beth root (trillium erectum) May stimulate the womb, causing miscarriage or premature labour.
Bitter orange (citrus aurantium) May cause heart irregularities and stroke.
Black cohosh (cimicifuga racemosa) Hormonal and womb-stimulating effects may cause premature labour.
Bloodroot (sanguinaria canadensis) May cause nausea, low blood pressure, skin irritation and lethargy. In high doses, can lead to coma.
Blue cohosh (caulophyllum thalictroides) May cause premature labour and developmental abnormalities, heart problems and strokes in your baby. Never take blue cohosh to start your labour.
Bugleweed (lycopus americanus) May cause thyroid gland enlargement, and may also affect pituitary hormones.
Caraway (carum carvi) May cause contractions, miscarriage or premature labour.
Cascara (rhamnus purshiana) Long-term use can cause fluid loss and potassium deficiency.
Celery seed (apium graveolens) May cause contractions, miscarriage or premature labour in medicinal amounts.
Camomile, roman (anthemis nobilis) May cause contractions, miscarriage or premature labour. May cause allergic reactions
Cinnamon (cinnamomum cassia) Large amounts can lead to liver toxicity.
Clary sage (salvia sclarea) Strong womb-stimulant. May cause miscarriage or premature labour if used before 37 weeks of pregnancy. Large doses in labour may cause fetal distress from very strong contractions. Never use clary sage to start labour.
Clove (sanguinaria canadensis) May cause blood-clotting problems and liver complications.
Comfrey (symphytum officinale) May cause abnormalities in your baby. Toxic to the liver and may be a cause of cancer (carcinogenic).
Cowslip (primula veris) May cause allergic skin reactions and tummy upset.
Devil's claw (harpagophytum procumbens) May cause miscarriage, diarrhoea, nausea, vomiting, headache, abdominal pain, allergic skin irritation and changes in blood.
Dong quai (angelica sinensis) May cause miscarriage, premature labour, diarrhoea, and sensitivity to sunlight. May be carcinogenic in large doses.
Elderberry (sambucus nigra) May cause nausea, vomiting, or severe diarrhoea if elderberries are not well-cooked before eating.
Eating unripe fruit or fruit juice made from unripe berries may cause weakness, dizziness or numbness.
Fennel (foeniculum vulgare) May cause contractions, miscarriage or premature labour, as well as allergic reactions
Fenugreek (trigonella foenum-graecum) Large amounts may cause contractions, miscarriage or premature labour.
Feverfew (tanacetum parthenium) May stimulate the womb, leading to premature labour. May cause nausea, diarrhoea or constipation, headache, abdominal pain and bloating.
Garlic (allium sativa) Medicinal amounts may potentially cause contractions, miscarriage or premature labour.
Ginseng, Asian (panax ginseng) May cause developmental abnormalities in your baby.
Ginseng, Siberian (eleutherococcus senticosus) May cause drowsiness, anxiety, irritability, breast tenderness and, in large doses, bleeding from the womb. Can cause palpitations, fast heartbeat and high blood pressure. Long-term use may cause sciatica and muscle spasms.
Golden ragwort (senecio aureus) May affect your baby's development and be toxic to your liver. Womb-stimulant that may cause miscarriage or premature labour.
Goldenseal (hydrastis canadensis) Stimulates the womb and may lead to miscarriage or premature labour. May also cause severe jaundice and possible brain damage in your baby.
Gotu kola (centella asiatica) Not enough is known about its effect in pregnancy to support its use. May cause liver toxicity.
Greater celandine (chelidonium majus) May be toxic to the liver and may cause hepatitis.
Horsetail (equisetum arvense) Can lead to deficiency of vitamin B1.
Juniper berry (juniperus communis) May cause miscarriage, and may be toxic to kidneys.
Lady's slipper (cypripedium parviflorum) May cause hallucinations. We don't have enough evidence to say it's safe.
Liqorice (glycyrrhiza glabra) May stimulate the womb, leading to miscarriage or premature labour. Increases blood pressure.
Lovage (levisticum officinale) May stimulate the womb, leading to miscarriage or premature labour.
Marjoram (origanum vulgare) Large amounts may cause womb contractions, miscarriage or premature labour.
Mistletoe (viscum album) May stimulate the womb and increase your blood pressure, leading to miscarriage or premature labour.
Motherwort (leonurus cardiaca) May stimulate the womb, leading to miscarriage or premature labour.
Mugwort (artemisia vulgaris) May cause miscarriage, premature labour, abnormalities in your baby and allergic reactions.
Mugwort sticks, which are burnt as part of an acupuncture treatment (moxibustion) to turn breech babies are, however, safe to use in pregnancy. These must be mild moxa specifically for turning breech babies.
Myrrh (commiphora molmol) May stimulate the womb, causing miscarriage or premature labour.
Oregano (origanum marjoricum) May stimulate the womb, leading to miscarriage or premature labour.
Parsley (petroselinum crispum) May stimulate the womb, leading to miscarriage. May also cause birth defects.
Nutmeg (myristica fragrans) May cause miscarriage or premature labour.
May cause hallucinations in large doses, and may react with pain-relieving drugs such as pethidine in labour.
Passion flower (passiflora incarnata) May stimulate the womb, leading to miscarriage or premature labour.
Pennyroyal (mentha pulegium) Toxic to the liver and kidneys. May stimulate the womb, leading to miscarriage and premature labour. May also cause dizziness, bloody vomiting, delirium, fits, raised blood pressure and blood-clotting disorders.
Peruvian bark (cinchona officinalis) May cause bleeding disorders and allergic reactions, headache, nausea, diarrhoea, vomiting and visual disturbance.
Poke root (phytolacca decandra) May stimulate the womb, leading to miscarriage or premature labour. May cause blood thinning and other alterations in the blood.
Pulsatilla (anemone pulsatilla) May stimulate the womb, leading to miscarriage or premature labour, as well as abnormalities in your baby.
Rhubarb (rheum officinale) May have a laxative effect, causing diarrhoea, nausea, and gastric bleeding. Prolonged use causes potassium deficiency, leading to muscle weakness and lowered bone density.
Rosemary (rosmarinus officinalis) May cause contractions if consumed in large amounts. The essential oil increases blood pressure and may trigger seizures if you have epilepsy.
Rue (ruta graveolens) May stimulate the womb, leading to miscarriage or premature labour, as well as liver or kidney failure.
Saffron (crocus sativus) May stimulate the womb if taken in large, medicinal amounts.
Sage (salvia officinale) May trigger bleeding and cause miscarriage. May reduce your milk supply due to its effect on hormones.
Sassafras (sassafras albidum) Contains safrole which may cause miscarriage, and may also be carcinogenic and toxic to the liver.
Shepherd's purse (capsella bursa-pastoris) May stimulate the womb, leading to miscarriage, or premature labour. May also cause thyroid problems.
St John's wort See St John's wort in pregnancy. May cause nausea and vomiting, headaches, tiredness, dizziness, confusion, dry mouth and anxiety attacks.
Tansy (tanacetum vulgare) May stimulate the womb, leading to miscarriage or premature labour. Long-term use may cause vomiting, fits, kidney and liver damage, breathing difficulties, irregular heartbeat, and loss of consciousness.
Thyme (thymus vulgaris) Allergic reactions may occur with prolonged use.
Valerian (valeriana officinalis) We don't know enough about valerian to say it's safe during pregnancy.
Verbena (verbena officinalis) May upset digestion and cause allergic reactions.
White horehound (marrubium vulgare) May stimulate the womb, leading to miscarriage and premature labour. May cause diarrhoea and skin irritation.
Wild yam (dioscorea villosa) Known to affect hormones. Not enough is known about it to say it's safe for pregnancy.
Wood betony (stachys officinalis) Reduces blood pressure and may cause diarrhoea.
Wormwood (artemisia absinthium) May stimulate the womb, cause miscarriage, premature labour, fits and kidney failure.
What are herbal remedies?
Herbal remedies that are safe in moderation
Herbal remedies to avoid in pregnancy and use with caution in labour
Herbal remedies to avoid in pregnancy and in labour
What are herbal remedies?
Herbal remedies are produced from plants. They are sometimes called herbal supplements, herbal medicines, or medicinal herbs.
Herbal remedies come in many forms, for example, powders, tinctures, infusions, teas, capsules, or tablets. They're available over the counter from health-food shops and pharmacies.
Whether you're trying for a baby, or are pregnant, consult a qualified medical herbalist before taking any herbal remedies. If you do decide to take herbal remedies or drink herbal teas, tell your doctor or midwife.
Some herbal remedies are powerful and they work in the same way as prescribed medications. Just because they are natural products, it doesn't mean they are always safe, especially during pregnancy.
Don’t take herbal remedies at all if you are already taking prescribed medication. This also applies when you go into labour, as you may need certain drugs to help you give birth.
If you're giving birth by planned caesarean section, stop taking herbal remedies at least two weeks before the date of your operation. Many herbal remedies cause blood thinning, and this could lead to extra bleeding during your caesarean.
For the same reason, don't take herbal remedies if you develop any bleeding problems during pregnancy.
Essential oils used in aromatherapy are also classified as herbal remedies. Read more about using aromatherapy in pregnancy.
Herbal remedies that are safe in moderation
The following herbal remedies are safe to use in moderation in pregnancy, but should be used with caution.
Herbal remedy Reason for caution in pregnancy
Camomile, German (matricaria chamomilla) May cause irritation and allergic reactions when used as a cream on the skin. Excessive use may stimulate the nervous system and cause insomnia.
Chilli (capsicum frutescens) May cause diarrhoea if used in large quantities in cooking.
Echinacea (echinacea purpurea) Small doses are safe in pregnancy, but only use for up to seven days.
May cause nausea, abdominal pain, diarrhoea, allergic reactions, breathlessness, heartburn, constipation, mouth ulcers, headache, dizziness, insomnia and disorientation.
Eucalyptus Safe as a diluted essential oil in small doses, and can be added to steam inhalation to relieve sinuses.
Only use for short periods. Undiluted oil on your skin may cause irritation. Don't swallow the essential oil, as it may upset your stomach.
Ginger (zingiber officinale) Large amounts may cause blood thinning, so avoid if you have a history of miscarriage or have any vaginal bleeding during your pregnancy. Excessive amounts may cause abdominal discomfort, heartburn and itchiness. Don't have more than about three teaspoons of grated root ginger a day.
Stop taking ginger at least two weeks before any planned surgery, including a caesarean.
Lavender (lavandula angustifolia) Do not use if you are taking drugs for a heart condition, or antacid medication for heartburn. Can lower blood pressure, making you feel faint.
Peppermint (mentha piperita) May cause heartburn, nausea, vomiting and allergic reactions, including skin irritation, when the oil is used on skin. May be a heart stimulant.
Do not use if you are taking drugs for heart complaints or antacid medication for heartburn.
(Red) Raspberry leaf (rubus idaeus) Do not take before 32 weeks. May stimulate the womb (uterus), and cause miscarriage or premature labour. In large doses, it may lengthen your labour.
Do not use if you have previously had a caesarean, have placenta praevia, bleeding in late pregnancy, are expecting twins, or if you have anaemia or high blood pressure. Do not use if you are taking iron tablets. See Can raspberry leaf tea bring on labour?
Senna (senna alexandrina) Long-term, frequent use, or high doses, has been linked to laxative-dependence and liver toxicity.
Don't use if you have had a previous miscarriage or threatened premature labour. May cause abdominal pain and cramps, nausea and diarrhoea.
Safe if used only for short periods of time in pregnancy. Do not use when taking drugs that have an effect on the kidneys, including drugs to reduce fluid retention and regulate your heartbeat.
advertisement
Herbal remedies to avoid in pregnancy and use with caution in labour
You should not use the following in pregnancy, but you can use them in labour on the advice of a registered medical herbalist. Discuss any herbal remedies that you may wish to use in labour with your midwife or doctor in plenty of time before your due date.
Herbal remedy Reason to avoid in pregnancy and use with caution in labour
Cotton root (gossypium herbaceum) Stimulates the womb.
False unicorn root (chamaelirium luteum) Stimulates the womb in labour. Do not use if you are taking lithium.
Jasmine (jasminum grandiflorum) May cause contractions, miscarriage or premature labour in pregnancy, but may be used in labour.
Lady's mantle (alchemilla xanthoclora) Stimulates the womb. May cause liver toxicity in very large doses.
Squaw vine (mitchella repens) May over-stimulate the womb, cause miscarriage or premature labour.
Herbal remedies to avoid in pregnancy and in labour
Do not take the following herbal remedies in pregnancy or when you are in labour.
Herbal remedy Reason to avoid in pregnancy and labour
Alder buckthorn (rhamnus frangula) May cause cramp-like discomfort and nausea.
Long-term use may cause potassium deficiency, leading to heart problems and muscle weakness.
Aloe vera (aloe barbadensis) May cause birth defects and miscarriage. However, skin creams and gels that contain aloe vera are safe to use on your skin.
Angelica (angelica archangelica) May cause womb contractions.
Anise/aniseed (pimpinella anisum) May cause skin irritation.
Arbor vitae (thuja occidentalis) May cause vomiting, diarrhoea, asthma, seizures, miscarriage, or premature labour.
Autumn crocus (colchicum autumnale) May affect cell division and lead to birth defects.
Barberry (berberis vulgaris) May cause very strong contractions and fetal distress. Also causes low blood sugar.
Beth root (trillium erectum) May stimulate the womb, causing miscarriage or premature labour.
Bitter orange (citrus aurantium) May cause heart irregularities and stroke.
Black cohosh (cimicifuga racemosa) Hormonal and womb-stimulating effects may cause premature labour.
Bloodroot (sanguinaria canadensis) May cause nausea, low blood pressure, skin irritation and lethargy. In high doses, can lead to coma.
Blue cohosh (caulophyllum thalictroides) May cause premature labour and developmental abnormalities, heart problems and strokes in your baby. Never take blue cohosh to start your labour.
Bugleweed (lycopus americanus) May cause thyroid gland enlargement, and may also affect pituitary hormones.
Caraway (carum carvi) May cause contractions, miscarriage or premature labour.
Cascara (rhamnus purshiana) Long-term use can cause fluid loss and potassium deficiency.
Celery seed (apium graveolens) May cause contractions, miscarriage or premature labour in medicinal amounts.
Camomile, roman (anthemis nobilis) May cause contractions, miscarriage or premature labour. May cause allergic reactions
Cinnamon (cinnamomum cassia) Large amounts can lead to liver toxicity.
Clary sage (salvia sclarea) Strong womb-stimulant. May cause miscarriage or premature labour if used before 37 weeks of pregnancy. Large doses in labour may cause fetal distress from very strong contractions. Never use clary sage to start labour.
Clove (sanguinaria canadensis) May cause blood-clotting problems and liver complications.
Comfrey (symphytum officinale) May cause abnormalities in your baby. Toxic to the liver and may be a cause of cancer (carcinogenic).
Cowslip (primula veris) May cause allergic skin reactions and tummy upset.
Devil's claw (harpagophytum procumbens) May cause miscarriage, diarrhoea, nausea, vomiting, headache, abdominal pain, allergic skin irritation and changes in blood.
Dong quai (angelica sinensis) May cause miscarriage, premature labour, diarrhoea, and sensitivity to sunlight. May be carcinogenic in large doses.
Elderberry (sambucus nigra) May cause nausea, vomiting, or severe diarrhoea if elderberries are not well-cooked before eating.
Eating unripe fruit or fruit juice made from unripe berries may cause weakness, dizziness or numbness.
Fennel (foeniculum vulgare) May cause contractions, miscarriage or premature labour, as well as allergic reactions
Fenugreek (trigonella foenum-graecum) Large amounts may cause contractions, miscarriage or premature labour.
Feverfew (tanacetum parthenium) May stimulate the womb, leading to premature labour. May cause nausea, diarrhoea or constipation, headache, abdominal pain and bloating.
Garlic (allium sativa) Medicinal amounts may potentially cause contractions, miscarriage or premature labour.
Ginseng, Asian (panax ginseng) May cause developmental abnormalities in your baby.
Ginseng, Siberian (eleutherococcus senticosus) May cause drowsiness, anxiety, irritability, breast tenderness and, in large doses, bleeding from the womb. Can cause palpitations, fast heartbeat and high blood pressure. Long-term use may cause sciatica and muscle spasms.
Golden ragwort (senecio aureus) May affect your baby's development and be toxic to your liver. Womb-stimulant that may cause miscarriage or premature labour.
Goldenseal (hydrastis canadensis) Stimulates the womb and may lead to miscarriage or premature labour. May also cause severe jaundice and possible brain damage in your baby.
Gotu kola (centella asiatica) Not enough is known about its effect in pregnancy to support its use. May cause liver toxicity.
Greater celandine (chelidonium majus) May be toxic to the liver and may cause hepatitis.
Horsetail (equisetum arvense) Can lead to deficiency of vitamin B1.
Juniper berry (juniperus communis) May cause miscarriage, and may be toxic to kidneys.
Lady's slipper (cypripedium parviflorum) May cause hallucinations. We don't have enough evidence to say it's safe.
Liqorice (glycyrrhiza glabra) May stimulate the womb, leading to miscarriage or premature labour. Increases blood pressure.
Lovage (levisticum officinale) May stimulate the womb, leading to miscarriage or premature labour.
Marjoram (origanum vulgare) Large amounts may cause womb contractions, miscarriage or premature labour.
Mistletoe (viscum album) May stimulate the womb and increase your blood pressure, leading to miscarriage or premature labour.
Motherwort (leonurus cardiaca) May stimulate the womb, leading to miscarriage or premature labour.
Mugwort (artemisia vulgaris) May cause miscarriage, premature labour, abnormalities in your baby and allergic reactions.
Mugwort sticks, which are burnt as part of an acupuncture treatment (moxibustion) to turn breech babies are, however, safe to use in pregnancy. These must be mild moxa specifically for turning breech babies.
Myrrh (commiphora molmol) May stimulate the womb, causing miscarriage or premature labour.
Oregano (origanum marjoricum) May stimulate the womb, leading to miscarriage or premature labour.
Parsley (petroselinum crispum) May stimulate the womb, leading to miscarriage. May also cause birth defects.
Nutmeg (myristica fragrans) May cause miscarriage or premature labour.
May cause hallucinations in large doses, and may react with pain-relieving drugs such as pethidine in labour.
Passion flower (passiflora incarnata) May stimulate the womb, leading to miscarriage or premature labour.
Pennyroyal (mentha pulegium) Toxic to the liver and kidneys. May stimulate the womb, leading to miscarriage and premature labour. May also cause dizziness, bloody vomiting, delirium, fits, raised blood pressure and blood-clotting disorders.
Peruvian bark (cinchona officinalis) May cause bleeding disorders and allergic reactions, headache, nausea, diarrhoea, vomiting and visual disturbance.
Poke root (phytolacca decandra) May stimulate the womb, leading to miscarriage or premature labour. May cause blood thinning and other alterations in the blood.
Pulsatilla (anemone pulsatilla) May stimulate the womb, leading to miscarriage or premature labour, as well as abnormalities in your baby.
Rhubarb (rheum officinale) May have a laxative effect, causing diarrhoea, nausea, and gastric bleeding. Prolonged use causes potassium deficiency, leading to muscle weakness and lowered bone density.
Rosemary (rosmarinus officinalis) May cause contractions if consumed in large amounts. The essential oil increases blood pressure and may trigger seizures if you have epilepsy.
Rue (ruta graveolens) May stimulate the womb, leading to miscarriage or premature labour, as well as liver or kidney failure.
Saffron (crocus sativus) May stimulate the womb if taken in large, medicinal amounts.
Sage (salvia officinale) May trigger bleeding and cause miscarriage. May reduce your milk supply due to its effect on hormones.
Sassafras (sassafras albidum) Contains safrole which may cause miscarriage, and may also be carcinogenic and toxic to the liver.
Shepherd's purse (capsella bursa-pastoris) May stimulate the womb, leading to miscarriage, or premature labour. May also cause thyroid problems.
St John's wort See St John's wort in pregnancy. May cause nausea and vomiting, headaches, tiredness, dizziness, confusion, dry mouth and anxiety attacks.
Tansy (tanacetum vulgare) May stimulate the womb, leading to miscarriage or premature labour. Long-term use may cause vomiting, fits, kidney and liver damage, breathing difficulties, irregular heartbeat, and loss of consciousness.
Thyme (thymus vulgaris) Allergic reactions may occur with prolonged use.
Valerian (valeriana officinalis) We don't know enough about valerian to say it's safe during pregnancy.
Verbena (verbena officinalis) May upset digestion and cause allergic reactions.
White horehound (marrubium vulgare) May stimulate the womb, leading to miscarriage and premature labour. May cause diarrhoea and skin irritation.
Wild yam (dioscorea villosa) Known to affect hormones. Not enough is known about it to say it's safe for pregnancy.
Wood betony (stachys officinalis) Reduces blood pressure and may cause diarrhoea.
Wormwood (artemisia absinthium) May stimulate the womb, cause miscarriage, premature labour, fits and kidney failure.
