Blackcurrant (Ribes nigrum)
Blackcurrant (Ribes nigrum) is the small dark-purple berry of a cool-climate European shrub, widely grown in the UK, Poland, and New Zealand and best known to British consumers as the blackcurrant in Ribena and in jams and cordials. It is naturally rich in vitamin C and in anthocyanin polyphenols, and is one of the most thoroughly catalogued berries in UK horticulture. Camden uses blackcurrant as a small supporting active in NB-553 (Vitamin C Acerola gummy), where the authorised UK vitamin C health claims attach to the combined vitamin C content rather than to the blackcurrant itself. Three practical things to know: 1. <strong>Blackcurrant is a food, and a vitamin C source.</strong> The UK Great Britain Nutrition and Health Claims Register lists no blackcurrant-specific health claims; the authorised vitamin C claims apply when a product's vitamin C content reaches 15% NRV per portion, regardless of source. 2. <strong>Eye-health and sports-recovery framings are not authorised UK claims.</strong> A New Zealand research programme around the CurraNZ blackcurrant extract has reported effects on cognitive performance, exercise recovery, and ocular blood flow in short trials. The evidence base is small, concentrated on a specific commercial preparation, and EFSA's botanical-claim evaluation is on hold — so these framings cannot be presented as authorised claims on a UK food-supplement product. 3. <strong>Blackcurrant seed oil is a different product class.</strong> Blackcurrant seed oil is the gamma-linolenic acid (GLA) source sometimes sold as a fatty-acid supplement (alongside evening primrose and borage oils). It is not the same as a blackcurrant berry extract and is covered separately in supplement evidence discussions.
Camden Medicals editorial · Last reviewed 12 May 2026 · Next review November 2026
- Cross-checked against
- NHS
- NICE
- BNF
- EFSA
- FSA
Camden's editorial team independently graded each health claim below on the strength of the published evidence — see the grade beside every condition.
- Class
- Botanical
- Typical daily dose
- Trials of standardised New Zealand blackcurrant extract (CurraNZ) have most commonly used 300 mg per day, providing approximately 100–200 mg of anthocyanins, for periods of days to weeks. Generic blackcurrant powder products typically deliver less anthocyanin per portion.
- Top use evidence
- Strong
On this page
What it is
Blackcurrant (Ribes nigrum) is a small woody shrub in the Grossulariaceae family, native to temperate Northern and Central Europe and Asia and now cultivated globally in cool-climate zones. The UK has been a long-standing commercial grower; Polish, Russian, and New Zealand production accounts for substantial global supply. The ripe berry is small, round, and very dark purple-black; it has a characteristic sharp, slightly astringent flavour that is rarely eaten raw and is most often processed into jams, cordials, juice (Ribena being the dominant UK consumer brand), and dried powder.
Blackcurrant berry is sold as a fresh fruit, a frozen fruit, a juice, a powder, and a concentrated extract in capsules. The New Zealand-grown CurraNZ commercial extract has accumulated the largest body of supplement-clinical research on a single standardised preparation. Blackcurrant seed oil, a separate product class extracted from the seed rather than the fruit pulp, is one of the dietary sources of gamma-linolenic acid (GLA) alongside evening primrose oil and borage oil.
At a glance
- The small dark-purple berry of Ribes nigrum — a food first, a supplement second.
- A high natural source of vitamin C and anthocyanins. UK-authorised vitamin C health claims attach to vitamin C content per portion, not to blackcurrant.
- Eye-health, sports-recovery, and cognitive framings are EFSA-on-hold for botanicals — not authorised UK food-supplement claims.
- Blackcurrant seed oil (GLA) is a different product class with different evidence and is not covered by this entry.
- Generally well-tolerated; pharmacist-disclose if you take anticoagulants or are managing iron status.
What people use it for
People including blackcurrant fruit, juice, or jam in their normal diet
Blackcurrant is a food. It contributes vitamin C and polyphenols to a varied diet. No specific health claim is authorised on blackcurrant itself.
Popular, not provenInsufficientAdults seeking a food-derived vitamin C source
Vitamin C from blackcurrant is bioavailable. Authorised UK vitamin C claims attach to a product's vitamin C content (≥15% NRV per portion), regardless of source. [5]
Some evidenceStrongRecreationally active adults exploring botanical recovery aids
Some short trials of standardised New Zealand blackcurrant extract (CurraNZ) have reported small effects on exercise economy, recovery markers, and lactate response. Effect sizes are modest, trials are small, and the evidence is concentrated on a specific commercial preparation. Blackcurrant is not part of NHS sports-medicine pathways.
Some evidenceLimitedAdults curious about eye / vision support
Some short trials of blackcurrant extract have reported small changes in ocular blood-flow markers and dark-adaptation. Clinical relevance is unclear and the trials are short. The NHS eye-health pathway (NHS Eye Health, optician review every 2 years, GP referral for new visual symptoms) applies independently of any supplement. [1]
Some evidenceLimited
How it works
Two mechanistic strands sit behind blackcurrant research. The first is the vitamin C content: blackcurrant berry is one of the higher natural sources of vitamin C in the temperate European diet, and the authorised UK vitamin C health claims (normal collagen synthesis, normal immune function, reduction of tiredness and fatigue, normal iron absorption, regeneration of the reduced form of vitamin E, and several others) become available to a product when the vitamin C content reaches 15% of the NRV per labelled portion. This claim pathway is attached to the vitamin C, not to the blackcurrant per se.
The second strand is the anthocyanin content. Blackcurrant is particularly rich in delphinidin-3-O-rutinoside and cyanidin-3-O- rutinoside, along with smaller amounts of other anthocyanins. Anthocyanins from blackcurrant appear in plasma after consumption and have been studied for effects on blood-flow markers, exercise recovery, and cognitive performance in short trials. The clinical literature is dominated by trials of specific standardised preparations (notably CurraNZ); effect sizes are modest and independent large-scale replication remains limited.
Common myths
Myth"Blackcurrant capsules are equivalent to drinking blackcurrant juice"
RealityThey are typically not, in either direction. A capsule extract delivers concentrated anthocyanin and vitamin C in a small dose; a glass of juice delivers a larger fluid volume with added sugars in the case of cordials. Read the actual per-portion vitamin C and anthocyanin declaration on the label rather than substituting one for the other on the basis of marketing.
Myth"Blackcurrant is a pilot's eye-vision food"
RealityThis is a long-standing folk story, often confused with the better-known bilberry pilot-vision story from World War II. Neither story is supported by clinical evidence at modern evidence standards. Eye-vision claims for botanical berries are not authorised UK health claims. [1]
Myth"Blackcurrant seed oil and blackcurrant berry are the same supplement"
RealityThey are not. Blackcurrant seed oil is extracted from the seed and is a source of gamma-linolenic acid (GLA), in the same product class as evening primrose oil and borage oil. Blackcurrant berry products (powder, extract, capsule) are the anthocyanin / vitamin C source. Different products, different evidence, different label claims.
Common online questions
Synthesised from the questions UK shoppers most often ask online about Blackcurrant (Ribes nigrum). Each answer is editorial and links to its evidence in the Sources list below.
Is blackcurrant the same as vitamin C?
No. Blackcurrant is a food source of vitamin C among other compounds. Authorised UK vitamin C health claims attach to a product''s vitamin C content (≥15% NRV per portion), regardless of whether the vitamin C came from blackcurrant, acerola, rosehip, or synthetic ascorbic acid. A blackcurrant- only label tells you the blackcurrant dose; what matters for the vitamin C claim is the milligrams of vitamin C declared. [5]
Does blackcurrant improve eyesight?
Some short trials have reported small effects on ocular blood-flow markers and dark-adaptation. Clinical relevance is unclear, the trials are short, and the findings do not support a "treats eye disease" claim. If you have new visual symptoms, the NHS pathway — optician review, GP referral where indicated — is what you need, not a supplement. [1]
Is blackcurrant safe in pregnancy?
Blackcurrant as a food (jam, juice, cordial, fresh or frozen fruit) is widely consumed during pregnancy without harm. Concentrated blackcurrant-extract supplements have limited supplemental safety data at higher doses; talk to your midwife or pharmacist before starting any new supplement during pregnancy. [3]
Can I take blackcurrant with prescribed medication?
Blackcurrant at food-supplement doses has not been associated with clinically meaningful drug interactions, but disclose all supplements to your prescribing pharmacist. High vitamin C intake can affect some laboratory tests; disclose to your anticoagulation clinic if you take warfarin, apixaban, rivaroxaban, dabigatran, or edoxaban. [4]
⚖️ The official position
What may lawfully be claimed about Blackcurrant (Ribes nigrum) in Great Britain. This is a regulatory position, not an evidence grade.
A health claim is authorised in Great Britain.
“Vitamin C contributes to the normal function of the immune system”
“Vitamin C contributes to the protection of cells from oxidative stress”
“Vitamin C contributes to the reduction of tiredness and fatigue”
This claim is authorised for use in Great Britain under the GB Nutrition and Health Claims regulation. A product may carry it when it provides at least 15% of the UK NRV per recommended daily portion.
Authorised UK health claims
Verbatim from the GB Nutrition and Health Claims Register (Reg 432/2012 as assimilated in GB). A product can carry these claims when it provides at least 15% of the UK NRV per recommended daily portion.
3 authorised claims — show / hide
- "Vitamin C contributes to the normal function of the immune system"
- "Vitamin C contributes to the protection of cells from oxidative stress"
- "Vitamin C contributes to the reduction of tiredness and fatigue"
🔬 Camden’s evidence review
The research Camden reviewed, graded on its strength. This is our own appraisal — it sits beneath the official guidance above, never above it.
Vitamin C status
StrongEvidencestrongBlackcurrant berry is a well-characterised dietary source of vitamin C. The authorised UK vitamin C health claims become available to a product when its vitamin C content reaches the 15% NRV threshold per portion, regardless of botanical source. [5]
Exercise performance and recovery
LimitedEvidencelimitedTrials of standardised New Zealand blackcurrant extract (CurraNZ) have reported small effects on exercise economy, post-exercise oxidative-stress markers, and recovery in recreationally active adults. Trials are short, populations are small, and the evidence is concentrated on a specific preparation. EFSA evaluation of botanical sports claims is on hold; no UK-authorised sports claims attach to blackcurrant.
Ocular blood flow and visual function
LimitedEvidencelimitedShort trials have reported small changes in ocular microcirculation and dark-adaptation markers with blackcurrant extract. Clinical relevance is unclear; trials are small and findings have not converged on a meaningful functional outcome. [1]
Cognitive performance markers
LimitedEvidencelimitedShort trials in healthy adults have reported small acute effects on attention, executive function, and mood markers. Findings are mixed and replication is limited.
Safety
Blackcurrant is a food and a well-tolerated supplement at typical doses. No specific health claim is authorised on blackcurrant in the UK.
Talk to your pharmacist or GP first if you:
- You take prescribed anticoagulants (warfarin, apixaban, rivaroxaban, dabigatran, edoxaban) or antiplatelets — disclose all supplements.
- You take iron supplements or are managing iron-deficiency anaemia — high vitamin C intake increases non-haem iron absorption.
- You have diagnosed kidney stones (especially oxalate stones) — high-dose vitamin C from any source can contribute to oxalate load.
- You are pregnant, breastfeeding, or trying to conceive — talk to your midwife or pharmacist before any new supplement.
Common side effects: Generally well-tolerated at typical doses. Concentrated berry extracts can cause mild GI complaints in some people.
Pregnancy and breastfeeding
Blackcurrant as a food (jam, juice, cordial, fresh or frozen fruit) is widely consumed during pregnancy without harm. Concentrated blackcurrant-extract supplements at high doses have limited supplemental safety data — talk to your midwife or pharmacist before starting any new supplement during pregnancy.
Blackcurrant as a food and at typical food-supplement doses is compatible with breastfeeding. Talk to your pharmacist before starting any new supplement while breastfeeding.
Talk to your GP, midwife, or pharmacist before starting any supplement during pregnancy or breastfeeding.
More clinical detail (for clinicians and informed readers)
Contraindications
- Known blackcurrant or Ribes-fruit allergy.
Drug interactions
- Anticoagulants and antiplatelets: high vitamin C intake from any source has theoretical pharmacokinetic effects on warfarin; disclose all supplements to your anticoagulation clinic.
- Iron supplements: vitamin C content increases non-haem iron absorption — usually a desirable interaction.
- Some laboratory tests can be affected by high vitamin C intake — tell your healthcare team.
This is not an exhaustive list. Always tell your prescriber and pharmacist about every supplement you take.
Common side effects
- Mild GI complaints — looser stools, mild abdominal discomfort at higher doses of concentrated extracts.
Rare side effects
- Allergic reactions — rare; berry-fruit cross-reactivity is possible in known fruit-allergy patients.
How to take it
- Typical supplemental range
- Trials of standardised New Zealand blackcurrant extract (CurraNZ) have most commonly used 300 mg per day, providing approximately 100–200 mg of anthocyanins, for periods of days to weeks. Generic blackcurrant powder products typically deliver less anthocyanin per portion.
- Timing
- Sports-context trials have typically used pre-exercise dosing 1–2 hours before activity.
How to spot quality
Look for
- Species declared (Ribes nigrum); cultivar / country of cultivation declared.
- Vitamin C content declared per portion in milligrams and as % NRV.
- For sports / cognitive framing: the standardised preparation named (e.g. CurraNZ) and the anthocyanin marker content declared.
- GMP-certified manufacture.
- No undisclosed added vitamin C — some "blackcurrant" products are fortified with ascorbic acid; this is fine but should be honest on the label.
Red flags
- Generic "blackcurrant extract" with no vitamin C declaration and no anthocyanin standardisation.
- Claims of treating or preventing eye disease, sports performance, or cognitive decline.
- Sports / eye / cognitive framing without naming the standardised preparation that the cited research used.
- "Blackcurrant seed oil" labelled or framed as the same product as the berry.
Commonly combined with
Other ingredients that share a biological pathway, cofactor relationship, or evidence-backed protocol with this one. Mechanisms below cite primary physiology — not folk pairing. Doses are literature ranges, not recommendations. Talk to your pharmacist or GP before changing your stack, especially if you take prescription medication.
Vitamin C
Strong evidenceBlackcurrant is a botanical vitamin C source; vitamin-c entry covers dose / NRV / authorised claims.
Vitamin C from blackcurrant enters the same plasma pool as vitamin C from any other source.
Evidence: UK Article 14 vitamin C health claims (NHCR). [5]
Doses studied: Blackcurrant + acerola + rosehip + ascorbic acid blends are common in gummy and tablet formats. Camden NB-553 uses this approach.
Found in Camden: Purifera™ Vitamin C Acerola Immune Complex 120 Capsules
Acerola
Limited evidenceTwo complementary botanical vitamin C sources, both commonly combined in UK gummies.
Acerola tropical anthocyanin-bearing fruit + blackcurrant temperate anthocyanin-bearing berry — vitamin C contribution plus different polyphenol matrices.
Evidence: UK Article 14 vitamin C claim attaches to combined vitamin C content.
Doses studied: Both used at modest milligram levels alongside synthetic ascorbic acid for declared NRV%.
Found in Camden: Purifera™ Vitamin C Acerola Immune Complex 120 Capsules
Rosehip (Rosa canina)
Limited evidenceThree-berry botanical vitamin C platform; complementary phytochemical profiles.
Rosehip carotenoid + galactolipid + blackcurrant anthocyanin + acerola anthocyanin — vitamin C contribution plus phytochemical diversity.
Evidence: UK Article 14 vitamin C claim attaches to combined vitamin C content.
Doses studied: Three botanicals at small milligram levels alongside synthetic ascorbic acid for declared NRV%. Camden NB-553 uses this approach.
Found in Camden: Purifera™ Vitamin C Acerola Immune Complex 120 Capsules