Red Raspberry Leaf Tea: What Research Shows About the Tea, Safety and Cautions

Read this first: pregnancy and raspberry leaf tea

• Pregnancy and breastfeeding. The EU herbal monograph for raspberry leaf states that safety during pregnancy and lactation has not been established, and that in the absence of sufficient data use during pregnancy and lactation is not recommended. [1] (EMA herbal committee, European Union, monograph compiled 2014.)
• What studies in pregnancy show. A 2021 systematic review of 13 studies, only six of them in humans, found that human studies have not shown any harm or benefit, and called the evidence base for pregnancy use weak. [2] A 2024 observational study of 91 records said its results cannot be relied on for the wider population and should not be taken as evidence that raspberry leaf is safe. [3]
• Tablets, not tea. A 2001 randomized, placebo-controlled trial gave raspberry leaf tablets (2 x 1.2 g a day, from 32 weeks until labor) to 192 low-risk first-time mothers in Sydney. It found no adverse effects for mother or baby and no shortening of the first stage of labor. The second stage was about 9.6 minutes shorter (mean difference 9.59 minutes), and forceps births were 19.3% with raspberry leaf versus 30.4% with placebo. The authors saw no significant differences on the other measures. [9] This was a tablet, not a cup of tea, so it does not show what the tea does.
• Herbal trials in pregnancy overall. A 2014 systematic review of herbal remedies in pregnancy (15 randomized trials and 16 other studies) said that although raspberry is believed to facilitate labor in traditional medicine, very few scientific data support that use. [10]
• Low blood sugar in gestational diabetes (one case). A 2016 case report described a 38-year-old woman with gestational diabetes who developed low blood sugar needing a lower insulin dose after drinking raspberry leaf tea at 32 weeks; it recurred when she restarted it. The authors suggested that women with gestational diabetes be cautioned and monitored more closely. [11] One case cannot show how common this is. If you have diabetes, tell your care team before using it.
• Breastfeeding. The U.S. National Library of Medicine LactMed entry says red raspberry leaf is a purported galactogogue (a milk-supply herb) but no scientifically valid clinical trials support this, that it is generally without side effects when used as a tea, but that no data are available on its safety in nursing mothers or their infants. [12]
• What to do. Talk with your midwife or doctor before using raspberry leaf tea while pregnant or breastfeeding. Our pregnancy and breastfeeding guide explains how to ask.

What red raspberry leaf tea is

Raspberry leaf tea is an infusion of the dried leaf of Rubus idaeus L., a plant in the rose family (Rosaceae). [4] The EU herbal committee describes raspberry leaf medicines as usually available as a herbal tea to be drunk. [5] It is a herbal tea (tisane), made from a leaf rather than the fruit; see Tisane vs Tea for the word. Check the botanical name and plant part on the label, because "raspberry" on a box can mean the fruit or a flavor (see herbal tea quality and labels). The plant profile is in Red Raspberry Leaf in Herbs & Botanicals.

Traditional use and what regulators concluded

These are two different things.

Traditional use: a 2021 review notes that childbearing women have been using various herbs to assist with pregnancy, labour and birth for centuries, and that raspberry leaf is one of the most common. [2] In one hospital survey of 121 postnatal women, 46 (38%) reported using raspberry leaf during pregnancy. [6] Popularity is not proof that it works.

Regulatory view: the EU herbal committee (HMPC) accepts raspberry leaf as a traditional herbal medicine, based on long-standing use, for minor spasms associated with menstrual periods, mild mouth or throat inflammation and mild diarrhoea. [5] It said that although there is insufficient evidence from clinical trials, the effectiveness is plausible, and it noted the lack of clinical studies for these uses. [5] Its monograph lists the menstrual-spasm use under a dry extract, and the herbal tea under the mild-diarrhoea use. [1] That is a regulatory category, not proof from trials. Raspberry leaf medicines should only be used in adults. [5]

What research found about the tea itself

Labels used here: promising but limited, insufficient evidence, preclinical (cells or animals).

Proper evidence not found for a randomized trial of raspberry leaf tea in pregnancy: a PubMed phrase search for "raspberry leaf tea" returned 9 records, and the two filtered as randomized trials were the healthy-adult glucose study above and a survey. [8] The survey's authors wrote that no experimental data exist to support the claims made for the tea. [6]

What the EU monograph describes (not advice)

For the mild-diarrhoea use in adults and the elderly, the monograph describes 1.5 to 8 g of comminuted leaf in 150 ml of boiling water as a herbal tea, three times daily, and says to consult a doctor if symptoms last longer than 3 days. [1] This describes an authorized product. It is not a recommendation, and it does not cover pregnancy. A clinician or pharmacist decides what is right for a person. See EU monograph tea amounts.

Safety details

• Side effects. At the time of the EU assessment, no side effects had been reported. [5] That is not proof of safety. The monograph also notes that tests on reproductive toxicity, genotoxicity and carcinogenicity have not been performed. [1]
• Medicines. The EU monograph lists interactions with other medicines as none reported. [1] Lack of reports is not proof of safety; ask a pharmacist, and see how interactions work.
• Children. The monograph says use under 18 years has not been established and is not recommended. [1]
• Liver, kidney, surgery, allergy. Proper evidence not found in the sources we read for raspberry leaf tea. Tell the surgical team about herbal teas before an operation (supplements before surgery).
• Quality. Herbal teas are not all tested the same way; see quality testing and certifications.