Raspberry
EVIDENCE: WEAKAlso sold as: Rubus idaeus, raspberry fruit extract, red raspberry leaf, raspberry ketones
Raspberry is a polyphenol-containing fruit. Evidence for fruit and leaf supplements is limited to traditional use and small studies. Raspberry ketones, sold for weight loss, have essentially no human evidence for that use.
Compiled by iSupplementReviews editorial team ·Updated 2026-10-13 · 4 sources
- Type
- Botanical fruit
- Studied dose
- not established for fruit extract; leaf tea 1.5–4.8 g/day (traditional)
- Best form
- whole-fruit extract for anthocyanins; red raspberry *leaf* is a different product (women's-health tradition)
- Our rating
- WEAK — Mostly small, animal, or traditional evidence
What is raspberry?
Raspberry (Rubus idaeus) contains anthocyanins, ellagic acid, vitamin C, and fiber. Supplements may use fruit extracts, leaves, or raspberry ketones. These are different preparations: the fruit is food, the leaf has traditional women’s-health uses, and ketones are sold for weight loss without meaningful human evidence.
The forms that matter — three different products
| Form | What it is | Evidence |
|---|---|---|
| Fruit extract/powder | Anthocyanins + ellagic acid | Polyphenol support, no outcome trials |
| Red raspberry leaf | Traditional uterine tonic | 2 small old trials on labor |
| Raspberry ketones | The aroma compound | Rodent data only — debunked for weight loss |
Where does it come from?
Europe and northern Asia, cultivated globally. The fruit is food; the leaf is harvested pre-fruiting in traditional herbal practice; the “ketones” in supplements are largely synthesized (the natural aroma is present in microgram quantities; extracting it from fruit at scale is uneconomical).
What is raspberry claimed to do?
Depends which product: fruit extract for antioxidant/polyphenol support; ketones for fat-burning and metabolism; leaf for pregnancy/labor support and menstrual comfort.
What does the research show?
| Claim | Evidence | Dose studied | Verdict |
|---|---|---|---|
| Weight loss (ketones) | Rodent mega-dose studies only (Morimoto 2005) | n/a in humans | No human evidence |
| Labor support (leaf) | 2 small old trials (Simpson 2001; Parsons 1999) | ~1.2–4.8 g leaf/day | Weak, mixed |
| Antioxidant/polyphenol support | Compositional data | food-level | Plausible |
| Anti-inflammatory (fruit) | Preclinical | — | Insufficient |
The ketones saga — a case study in supplement marketing
Morimoto et al. (2005) showed raspberry ketone prevented weight gain in mice on high-fat diets, at doses translating to implausible human quantities. The supplement industry built a billion-dollar category on that rodent paper; no human weight-loss trial has ever shown benefit. It remains the cleanest example of “mechanism sounds plausible, human evidence never arrived.”
The leaf — the traditional product
Simpson et al. (2001) randomized ~190 women to raspberry-leaf tablets in late pregnancy: a modest shortening of second-stage labor and fewer forceps deliveries. Real but small, and never meaningfully replicated since. Parsons 1999 found similar weak signals. Two small old trials are the entire human evidence base for a centuries-old remedy.
The fruit — nutrition
Anthocyanins, ellagic acid, vitamin C: real polyphenol density, plausible antioxidant contribution, no targeted human outcome trials. It earns a place as nutritional support, not as an active.
What doesn’t raspberry do?
Ketones don’t burn fat (debunked); fruit extract has no demonstrated targeted outcomes at supplement doses; the leaf isn’t an established labor aid; it’s a tradition with weak preliminary support.
What dose was studied?
No established dose for fruit extract; outcome trials essentially don’t exist. Leaf tradition runs ~1.5–4.8 g/day as tea, third trimester only.
Side effects
Fruit: none meaningful. Leaf: mild nausea/diarrhea; traditional caution against first-trimester use. Ketones: stimulant-like jitteriness; they’re often blended with caffeine.
Drug interactions
Minimal documented; leaf products are sometimes cautioned with uterine-acting medications; fruit is food.
Who should not take raspberry products?
Pregnant women shouldn’t use the leaf before the third trimester without midwife guidance; everyone should be skeptical of ketone products entirely.
What the authorities say
There are no dedicated monographs assessing raspberry supplements. The limited research does not provide an established institutional assessment of their claimed benefits.
What to know about raspberry
Distinguish raspberry fruit, leaf, and ketones when reading a label. The fruit supplies plant compounds, leaf evidence is limited, and weight-loss claims for ketones are unestablished. A shared name does not make their evidence interchangeable.
Frequently asked questions about Raspberry
Do raspberry ketones work for weight loss?
No human evidence supports it; it's one of the industry's most famous marketing myths. The rodent studies that launched the craze (Morimoto et al., 2005) used doses equivalent to kilograms of product in humans, and no human weight-loss trial has ever shown benefit. The classic 'sounds plausible, never proven' ingredient.
Is raspberry fruit extract good for you?
It's a legitimate source of anthocyanins, ellagic acid, and vitamin C: real polyphenol content with plausible antioxidant benefits. But there are no meaningful human outcome trials for raspberry fruit extract itself; it's food-grade nutritional support, not a therapeutic.
What is red raspberry leaf used for?
A different product: the leaf is a traditional women's-health herb, famous as a 'uterine tonic' taken in late pregnancy to ease labor. Evidence is thin: two small old trials suggested it might shorten second-stage labor (Parsons 1999; Simpson 2001), but nothing is established.
Is raspberry in blends a meaningful ingredient?
Usually it's there for antioxidant/polyphenol content or label appeal; the fruit has good nutrient density but no targeted evidence at blend-level doses. filler at worst, mild polyphenol support at best.
Is raspberry leaf safe in pregnancy?
Traditional guidance says third trimester only; it's a uterine-active herb. The small trials found it reasonably tolerated late in pregnancy, but it's one to run past a midwife, not a supplement to self-start.
References
- [1]Morimoto C et al. — Anti-obese action of raspberry ketone (Life Sci, 2005 — rodent study)
- [2]Simpson M et al. — Raspberry leaf in pregnancy: safety and efficacy (J Midwifery Womens Health, 2001)
- [3]Parsons M et al. — Raspberry leaf and labor outcomes (Aust small study, 1999)
- [4]USDA FoodData Central — Raspberry nutrient composition (anthocyanins, ellagic acid, vitamin C)
Products we reviewed containing Raspberry
Based on recorded labels or seller-described formulas. Inclusion does not establish a match to the strains, preparations or amounts studied here; check each review's disclosure limits.