I don't think I've met a pregnant woman in my circles who hasn't heard of Red Raspberry Leaf (RRL).
20 years ago when I first started practising as a naturopath it was definitely not as popular as it is today.
Even Google will give you 19 million results within less than a second!
Its botanical name is Rubus idaeus but most refer to it as simply 'raspberry leaf.'
Naturopaths and herbalists will often refer to it as Rubus or abbreviate it to 'RRL'.
In the herbal dispensary it's classified as a partus preparator, or partus prep for short. Partus meaning 'labour', preparator meaning 'preparation'.
Of all the herbs that are often considered for labour preparation, raspberry leaf products appear to be the safest and the most popular.
Various studies show between 7% and 58% of pregnant women use raspberry leaf.
That equates to between 21,000 and 174,000 of the 300,000 births a year in Australia!
So what's the deal with raspberry leaf?
- Is it safe? What research is there?
- How does it help with preparing the uterus for labour?
- When is the best time to start using it?
- How much should I have?
- Which is best: tea, infusion, tablets or tincture?
- Why is my midwife and naturopath telling me different things?
- Can I have too much?
- Can I also use after the birth?
Raspberry leaf has been used in Europe for centuries, certainly as early as the 6th century. It is native to Europe, North America and temperate Asia.
The use of the wild variety, Rubus strigosus has been documented in western medicinal writings since the 16th century as a traditional medicine.
By the 17th Century, raspberry leaves had garnered the interest of the famous botanist, herbalist, and physician, Nicholas Culpeper, who wrote that the plant was:
“very binding and good for fevers, ulcers, putrid sores of the mouth and secret parts, for stones of the kidneys and too much flowing of the women’s courses.”
In ‘King's American Dispensatory’ (1898), it's described that "the leaves and fruits are the parts of the plant that are used for medicinal purposes. The leaves impart some of their constituents to water, giving to the infusion an odour and flavour somewhat similar to that of some kinds of black tea."
The traditional medicinal use of raspberry leaf has been continuously documented in handbooks, pharmacopoeias and scientific literature. Noted as a treatment for various disorders most commonly related to menstruation, parturition (childbirth) and ailments of the gastrointestinal tract.
According to the literature, the traditional use of raspberry leaf as a tonic-like tea to support a healthy pregnancy and to facilitate childbirth, seems to be most widespread.
In 1941, several constituents (namely alkaloids) collectively named 'fragarine' were discovered in the leaf.
Fragarine helps uterine muscles to contract smoothly and uniformly, reducing cramping during menstruation while also lessening heavy menstrual bleeding. This effect has been well-documented in animal studies but the herb and its effects have not been rigorously tested in humans.
Interestingly, these constituents were shown to have a relaxing effect on the pregnant uterus. Contractions were diminished in force and frequency, and occurred at evenly spaced intervals. Secondary contractions were also eliminated. In addition to these effects, other researchers found that if the uterine muscle was relaxed, the herb actually induced contractions.
If you're feeling confused at this point, I understand. Stay with me.
It seemed the active constituents of raspberry leaves seemed to possess contradictory effects - on one hand relaxing the uterine muscle and on the other, initiating contractions.
If the effect of raspberry leaves was primarily to relax the uterus then how could the herb actually assist with labour? The researchers were also perplexed.
In 1954, another team of researchers isolated several constituents from the leaves - some of which increased uterine contractions, while others relaxed the uterus. They too noted these opposing actions stating the use of raspberry leaf was "difficult to assess..."
Then in 1970, the leaf itself (and not just the isolated constituents of it) was tested on the smooth muscle of the uterus. This testing brought about a proposal of why raspberry leaf was beneficial. The researchers suggested...
Raspberry leaf would prevent or reduce incoordinate uterine action - a common cause of difficulty and failure to progress in labour - by regulating the action of the uterine muscle.
So given this, I'm happy to call raspberry leaf the great regulator. Helping to prepare the uterus for an effective birth by relaxing over-tense muscles and toning over-relaxed muscles.
This in turn supports the uterus to contract effectively during labour. As this requires a balanced action between contraction and relaxation of the uterus ie. contraction on, contraction off.
Every mother would love an efficient, physiological and progressive labour without any undue stress on baby in the process (IV hormonal drip I'm lookin' at you).
This also explains why raspberry leaf does not start labour or promote contractions. Instead, it strengthens the pelvic and uterine muscles so that once labour does start, it's more efficient.
When taken throughout pregnancy, particularly in the third trimester it's also thought to help facilitate a safer third stage of labour, preventing haemorrhage.
Studies & Safety
One study in 1999 consisted of 108 mothers; 57 (52.8%) consumed raspberry leaf products, whereas 51 (47.2%) were in the control group and did not.
The findings suggested that raspberry leaf can be taken safely during pregnancy to shorten labour with no expected side effects for women or their babies.
The study also reported a decreased likelihood of pre- and post term gestation (premature labour or going 'over-due'), fewer obstetric interventions, including decreased amniotomy (OB/midwife breaking the bag of water), caesarean section, forceps delivery and vacuum extraction in the group that had taken raspberry leaf.
Then in 2001 some of this research team continued their investigations. They published a further study just focusing just on raspberry leaf tablets, not the tea.
This double-blind, randomised, placebo-controlled trial consisted of 192 low-risk, first times mums who birthed their babies between May 1999 and February 2000 at a large tertiary-level hospital (Westmead Hospital) in Sydney, Australia.
The aim of the study was to identify the effect and safety of raspberry leaf tablets (2 x 1.2 g per day), consumed from 32 weeks' of pregnancy until labour, on labour and birth outcomes.
Raspberry leaf tablets had no adverse effects for mother or baby, but in this study they did not shorten the first stage of labour.
The study did find that there was a shortening of the second stage of labour (by around 10 minutes) but an 11% lower rate of forceps deliveries between the raspberry leaf group and the control group (19.3% vs. 30.4%).
When I see these studies and these results I immediately wonder about the variables. As a doula I'm aware of all the influencing factors on labouring women in hospitals. Did any women have inductions or have their labour augmented? How many women had pain relief or epidurals? How many were confined to the bed with continuous fetal monitoring? Did any have additional birth support like a doula? Were active birth positions adopted? etc etc
I also find the stats for the use of forceps alone a little concerning. Statistically their use is more common with the use of epidurals. Unfortunately I couldn't find these finer details. I think we're well overdue for a new study that's not 20 years old.
Raspberry leaves have very high levels of manganese, moderate levels of iron, calcium, magnesium, selenium, plus the vitamins A, B, C and E.
It's a gentle, effective and nutritive herb.
When & what form
You'll find varied opinions on when to start taking raspberry leaf. These recommendations also depend on the preparation used - teabags, loose tea, tablet or herbal tincture.
Those on the very conservative side say to wait until the last 4-5 weeks of pregnancy ie. around 35-36 weeks before taking any form.
At the other end of the spectrum some say you may begin taking it as a tea during the first trimester.
Using the tablet form is typically recommended from 32 weeks onwards. The dose may increase slowly over the weeks until full term.
The herbal tincture may also be offered with an increasing dose from around 34 weeks.
The effects of raspberry are typically cumulative, so its more the case of the longer you've taken it, generally the better.
Typically midwives steer on the side of caution with their suggestions. This makes sense as recommending herbs is not technically (or legally) within their scope of clinical practice.
Us naturopaths/herbalists are often more comfortable with preparations, dosing and timings. As herbs are at the core of our modalities - and totally our jam!
Tablets, tea or infusion?
Ask any naturopath or herbalist and I'd say over 90% would recommend the tea over the tablets.
Some studies performed in vitro (in lab) have shown that there is higher effectiveness in raspberry leaf tea preparations (water extracts), followed by dried herb capsules or tablets.
It's just something I prefer to keep old school here.
The dried leaves are very fluffy and can clump together. So when adding "1-2 teaspoons per cup" consider this aspect and perhaps compress the leaves so you receive a more accurate measurement.
Although it's a vibrant and fruiting plant, preparations made from the leaves taste nothing like raspberries - unfortunately.
The taste of the tea is quite bland, some liken it to green or black tea. It also contains a fair amount of natural tannins (up to 15%) so adding in a little honey and/or lemon may help the taste factor a little. Some women don't mind the taste at all and enjoy as is.
The stronger the brew the better medicinal potency. So I suggest you consider making an infusion instead of a tea.
An infusion is when you pour the boiling water over the herbs and let it sit for 4-8 hours before straining some off to drink. This works well as a batch method in a large plunger, large tea pot or even a saucepan.
When making it up the ratio is around 1 cup of boiling water for every 1-2 teaspoons of dried herb. Depending on how many you're having a day, you can make up a day's worth the night before or first thing in the morning. Discard any leftovers after 24 hours.
A tea is when you only wait 15 minutes or so before straining off and drinking.
You may also add in another herb eg. peppermint, spearmint, lemongrass or rosehips to help enliven the flavour. Adding nettle leaves will bump up the nutrients too.
My raspberry leaf recommendations:
🌿 I highly recommend the loose leaf over the tea bags. The quality is often incomparable. Plus you actually get to see what you're getting. I also prefer an infusion over a tea. You get more bang for your buck from a long steeped infusion.
🌿 Begin with 1 cup per day during the 2nd trimester. It may be taken as early as 12 weeks but I consider 24-28 weeks onwards a more reasonable and beneficial starting point.
🌿 At 30-32 weeks, increase it to 2 cups per day.
🌿 At 36 weeks, increase it to 3 cups per day.
🌿 At 38 weeks, increase it to 4 cups per day.
🌿 At 39 weeks, stay on 4 cups or up it to 5 cups per day until labour begins.
🌿 You may even sip on it during early or established labour.
You may drink it warm, chilled or even iced in the summer months.
For the definite non-tea drinkers, then yes the tablets or the tincture may be better suited for convenience and compliance.
A herbal tincture is an alcohol base extraction of the herb. It gives a high potency preparation which means you don't need to take much to get the medicinal effect.
It has high absorbency and fast-acting properties. Given that only a very small/negligible amount of alcohol is consumed, it remains a very safe and effective way of using herbs. Taken as directed, tinctures are considered safe for late pregnancy.
I usually suggest the raspberry leaf tincture is taken from 34 weeks onwards.
I include a dosage regime that increases over the weeks, from 34-40 weeks.
It may also be continued beyond 40 weeks until labour begins.
Some mums notice Braxton Hicks contractions/tightenings pick up a little after - or even while they're having a cup of raspberry leaf tea. I certainly noticed this toward the pointy end of my pregnancies.
I've also noticed this to be more likely the case with mums that have been taking it quite regularly throughout their third trimester.
This is not a side-effect as such, as we know the herb acts on the uterine muscle.
If of course they are very uncomfortable or at worst painful, it may be a sign to reduce your intake a little or even take a break for a couple of days. It's important to note here that dehydration can lead to an 'irritable' uterus or painful tightenings, so can insufficient magnesium in the diet. Just some things to consider and/or address.
As mentioned, the leaves contain natural tannins. These have been shown to reduce intestinal inflammation and stop loose stools. Given this there is a possibility this may have some effect on your bowel function ie. slowing it down. I've not had a lot of feedback from mums noticing anything out of the ordinary of their 'pregnancy bowel habits'. But something to note.
After the birth?
If you have some left over after baby has arrived then you may continue to drink 1-2 cups tea per day in those early days/weeks postpartum. It may aid in the involution of the uterus and after pains.
It's high nutrient content may also help to enrich breastmilk, though over-consumption may cause supply issues due to raspberry’s astringency. Just keep an eye on this and simply stop if concerned.
🌿 🌿 🌿
Rubus provides us with unique properties as a uterine tonic with an affinity for pregnancy and birth preparation.
I'd really love to see further investigations and well-designed, randomised, controlled studies involving sufficient sample sizes of women in the near future.
References available on request.