Hermetica Superfood Encyclopedia
Red raspberry leaf contains fragarine, an alkaloid that tones uterine muscles and may reduce labor complications. Clinical studies show it can shorten the second stage of labor by approximately 9.59 minutes and reduce forceps delivery rates.
Origin & History
Red raspberry leaf comes from Rubus idaeus, a perennial shrub native to Europe and Asia. The leaves are harvested, dried, and prepared in various commercial forms including teas, capsules, and tablet extracts. The leaf extract contains polyphenolic compounds with antioxidant properties and active constituents that affect smooth muscle function.
Scientific Research
The primary evidence comes from a double-blind, randomized, placebo-controlled trial (PMID: 11370690) with 192 women showing shortened second stage of labor and reduced forceps deliveries. A systematic integrative review (PMID: 33563275) analyzing 13 studies concluded that human studies have not shown harm but evidence of benefit remains limited. Researchers emphasize that robust randomized controlled trial evidence is urgently needed.
Preparation & Dosage
Clinically studied dosage: 2.4 g/day (1.2 g twice daily) from 32 weeks gestation. Traditional recommendations range from 4-8 g/day according to the British Herbal Medicine Association. Women typically consume 1-6 cups of tea daily, with initiation varying from 8 to 38 weeks gestation. Consult a healthcare provider before starting any new supplement.
Nutritional Profile
Red Raspberry Leaf (Rubus idaeus) is a polyphenol-rich botanical with the following key constituents: Tannins (primarily ellagitannins including sanguiin H-6 and lambertianin C) at approximately 15-20% dry weight, representing the dominant bioactive fraction. Flavonoids including kaempferol, quercetin, and tiliroside at 1-3% dry weight. Fragarine (a unique alkaloid-like compound specific to Rubus species) present at trace concentrations, historically associated with uterotonic properties though precise quantification in standardized preparations remains limited. Vitamin C (ascorbic acid) at approximately 25-40mg per 100g dried leaf. Mineral content includes magnesium (~400mg/100g dried), potassium (~1,000mg/100g dried), calcium (~350mg/100g dried), iron (~3-4mg/100g dried), and manganese (~4-5mg/100g dried). Dietary fiber comprising approximately 10-15% dry weight (primarily insoluble cellulose and hemicellulose). Protein content is modest at approximately 12-15% dry weight. Gallic acid and ellagic acid are present as hydrolysis products of ellagitannins. As a tisane (tea infusion), bioavailability of water-soluble polyphenols is moderate; tannin absorption is limited due to protein-binding affinity in the gastrointestinal tract. Fat-soluble constituents are minimally extracted in standard aqueous preparations.
How It Works
Fragarine alkaloid acts on smooth muscle fibers in the uterus, promoting coordinated contractions during labor. The compound also influences prostaglandin synthesis pathways, potentially reducing excessive bleeding. Additional tannins provide astringent properties that may strengthen uterine wall integrity.
Clinical Evidence
A double-blind RCT with 192 women demonstrated that red raspberry leaf shortened the second stage of labor by 9.59 minutes compared to placebo. The same study showed reduced forceps delivery rates with moderate evidence strength. Preliminary observational data suggests lower postpartum hemorrhage rates (14% vs 28%), though this requires confirmation in controlled trials. Evidence is strongest for labor-related outcomes but limited for other purported benefits.
Safety & Interactions
Red raspberry leaf is generally well-tolerated during pregnancy's second and third trimesters. First trimester use is not recommended due to potential uterine stimulation effects. No significant drug interactions have been documented, but caution is advised with anticoagulant medications due to potential bleeding risk reduction. Women with previous complicated pregnancies should consult healthcare providers before use.
Also Known As
Frequently Asked Questions
How much red raspberry leaf should I take during pregnancy?
When should I start taking red raspberry leaf before labor?
Can red raspberry leaf cause early labor or miscarriage?
What's the difference between red raspberry leaf tea and capsules?
Does red raspberry leaf help with postpartum recovery?
What does the clinical research show about red raspberry leaf's effects on labor duration and delivery outcomes?
Who is red raspberry leaf most beneficial for, and are there groups who should avoid it?
Does red raspberry leaf interact with common medications, particularly those used during pregnancy or labor?
Conditions This May Help
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