IngredientsA clementine (Citrus × clementina) is a tangor, a citrus fruit hybrid between a willowleaf mandarin orange (C. × deliciosa) and a sweet orange (C. × sinensis). Clementines belong to the Rutaceae family, which includes grapefruit, pomelo, orange, lemon, kumquat, mandarin, and calamansi.
The taxonomy of mandarin and mandarin-like fruits (including the clementine) is very complex, because there are many interspecific hybrids and cultivars, some of whose origins and taxonomic relationships are uncertain. Swingle's classification (1943) recognizes five groups belonging to a single species, C. reticulata Blanco. However, according to Tanaka's classification (1954), all mandarin and mandarin-like fruits belong to 36 species. In this classification, the clementine is considered to be a distinct species, C. clementina Hort. Within the NCBI taxonomy, Citrus clementina falls in the lineage: Eukaryota → Viridiplantae → Streptophyta → Magnoliopsida → Sapindales → Rutaceae → Aurantioideae → Citrus.
Citrus clementina, commonly known as clementine, is a type of citrus fruit that belongs to the Citrus genus, which is characterized by modified berries known as hesperidia, and is a hybrid primarily derived from mandarins and other citrus species. Some sources have attributed an earlier origin for the hybrid, pointing to similar fruit native to the provinces of Guangxi and Guangdong in present-day China, but these are likely distinct mandarin hybrids, and genomic analysis of the clementine has shown it to have arisen from a cross between a sweet orange (Citrus × sinensis) and the Mediterranean willowleaf mandarin (Citrus × deliciosa).
The fruit is small, usually 2 to 3 inches (5 to 7.5 cm) in diameter, with smooth, glossy, deep orange skin. The flesh is juicy and sweet with minimal acidity, and the segments separate easily without much pith, making them incredibly convenient to eat. Clementines can be separated into 7 to 14 segments. There are three types of clementines: seedless clementines, clementines (maximum of 10 seeds), and Monreal (more than 10 seeds).
The fruit is nearly always seedless when grown in isolation, though cross-pollination with other citrus can produce seeds, and it matures early in the season, typically ripening from October to December in suitable climates. They are widely cultivated in Mediterranean countries, California, and Florida, and are typically available from late fall through winter.
Clementines are commonly eaten fresh, but they can also be used in salads, desserts, and juices. Their essential oil is also used in aromatherapy and perfumery. Often sold under brand names like Cuties or Halos, clementines are ideal for fresh eating, salads, and desserts. The essential oil is cold-pressed from the peel. The oil is extracted from the peel of the fruit in its purest form before it is further processed and bottled. Cold pressing involves putting the rind under mechanical pressure to burst the oil sacs in the rind of the clementine, releasing the essential oil which is then separated and collected.
The clementine is a spontaneous citrus hybrid that arose in the late 19th century in Misserghin, Algeria, in the garden of the orphanage of the French missionary brother Clément Rodier, for whom it would be formally named in 1902. In the 19th century, citrus fruit cultivation became widespread around the Mediterranean region, and included mandarines, which have a sweet flavour but grow slowly with irregular fruit quality. In 1892, Brother Clément (1839–1904), head of cultivation at an orphanage in Oran in Algeria, crossed an orange with a mandarin orange. This union produced an easy-peeling fruit with no pips and a very sweet flavour, the clementine, which also ripens much faster than a mandarine.
The hypothesis is also emerging that the hybrid is much older and comes from China or Japan. After the first hybridizations at the beginning of the twentieth century, it was soon evident that it was a new species of Citrus, given that the characteristics remained unchanged over time and the systematic reproduction of the citrus fruit did not give any problems.
In addition, clementines can be kept for longer, a fact which soon made them very popular. Today, you can find clementines growing in Africa, Asia, Europe, and North America. In California, they are popular during the Christmas season and reach peak ripeness from October through December. Clementine (Citrus × clementina) is a typical autumn citrus cultivated in Italian temperate areas, especially in the Calabria region (South of Italy), where it finds the appropriate conditions for optimal ripeness.
While clementines are not a major component of traditional medicine systems, citrus fruits, in general, have a long history of use in various traditional practices. In traditional Chinese medicine, citrus fruits are considered to have cooling properties and are used to help balance the body's energy. They are often recommended for relieving heat-related symptoms and promoting digestion. In some cultures, the peel of citrus fruits is used to make teas or infusions to aid in digestion and relieve nausea. The aroma of clementines and other citrus fruits is often used in aromatherapy to uplift mood and reduce stress.
The genus Citrus belongs to family Rutaceae, which is characterized by trees and bushes. Citrus species are extensively cultivated throughout the world because of their multiple health benefits for humans and their applications in pharmaceutical and food industries. Because the clementine was only formally named in 1902 and arose as a spontaneous hybrid, it does not appear in pre-modern pharmacopeias or traditional healing texts as a distinct botanical entity; historical references to its parent species—mandarin and sweet orange—are more pertinent to understanding its traditional medicinal lineage.
Rich in vitamin C (48.78 mg per 100 g), clementines boost the immune system and support skin health through collagen production. They contain dietary fiber (1.76 g per 100 g) which aids digestion and promotes gut health. Low in calories (47 per 100 g) and nearly fat-free, making them a healthy option for weight management. A single clementine, about 74 grams, offers roughly 35 calories, 9 grams of carbohydrates, and 1 gram of fiber. Additionally, they contain small amounts of folate, supporting cell function and growth.
Clementines and other citrus fruits contain natural plant chemicals called flavonoids, which help regulate the growth of the plant and protect it from pathogens and disease, 2018 research explains. Mandarin fruits, like clementines, have the highest content of flavonoids, compared with other citrus fruits, according to a 2019 review.
The principal flavonoid subclasses found in clementines are flavanones and polymethoxylated flavones (PMFs). Key individual compounds include:
Beta-cryptoxanthin is one of the important carotenoid compounds present in bright red or orange-colored fruits and vegetables, such as clementine, mandarin, and orange. While beta-cryptoxanthin acts as a potent antioxidant, carotenoid compounds are precursors for vitamin A formation in the body that maintains eye, cellular, and reproductive health. This carotenoid has protective health effects including bone formation and provitamin A activity.
Their oils, like other citrus fruits, contain mostly limonene as well as myrcene, linalool, α-pinene and many complex aromatics. Analytical profiling confirms the dominance of limonene: the limonene percentage in clementine essential oil (EO) is approximately 96–97%. In peel EOs, limonene is the dominant compound, while sabinene, linalool, limonene, δ-3-carene, and trans-β-ocimene are key constituents of clementine mandarin leaf EO; sabinene and linalool are the two major components of the EOs from the leaves of clementine.
Sabinene, β-pinene, D-limonene, linalool, and terpinen-4-ol elicit antiaging activity of the clementine oil. Clementines also contain limonoids, including nomilin; clementine includes nomilin content as well. It is a powerful glycoside from the limonoid family with antioxidant, antiviral, anticancer, and neuroprotective effects.
The fruit's antioxidant properties are attributed to its high vitamin C content and the presence of other bioactive compounds, such as flavonoids and carotenoids. Vitamin C acts as a direct free-radical scavenger. It helps protect against infections by promoting the function of white blood cells and acting as an antioxidant to combat free radicals. As a strong antioxidant, vitamin C reduces oxidative stress in the body, potentially lowering the risk of chronic diseases like heart disease and certain cancers.
Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases due to its anti-inflammatory, antioxidant, lipid-lowering, and insulin-sensitizing properties. The pharmacological activities of nobiletin may be underpinned by modulation of signaling cascades, including PKA/ERK/MEK/CREB, NF-κB, MAPK, Ca²⁺/CaMKII, PI3K/Akt1/2, HIF-1α, and TGFβ signaling pathways.
Nobiletin and tangeretin are citrus peel polymethoxyflavones possessing anticancer, antimetastatic, and anti-inflammatory activities. Their effects on LPS- and IgE-mediated stimulation of human intestinal mast cells (hiMC) have been analyzed. MC isolated from human intestinal tissue were treated with different concentrations of nobiletin or tangeretin prior to stimulation via LPS/sCD14 or IgE-dependently; degranulation, pro-inflammatory cytokine expression and phosphorylation of ERK1/2 were examined. Nobiletin and, to a lesser extent, tangeretin could be considered as anti-inflammatory nutraceuticals by reducing release and production of proinflammatory mediators in mast cells.
Hesperidin and hesperetin counteract atherosclerosis, a key contributor to heart disease, by ameliorating lipid profiles, inhibiting plaque formation, and reducing inflammation. These flavonoids protect against drug-induced cardiotoxicity, safeguarding the heart from injury developed by arsenic trioxide, cisplatin, and doxorubicin. They enhance endothelial function, regulate blood pressure, and counteract oxidative stress. Nobiletin can reduce the circulating concentrations of very low-density and low-density lipoproteins and inhibit macrophage foam-cell formation at the site of lesion development within a vessel wall, thus preventing atherosclerosis.
Food components such as flavonoids can alter the pharmacokinetics of drugs by inhibiting or increasing activities of drug-metabolising enzymes and drug transporters that have important roles in absorption, distribution, metabolism, and excretion. The results demonstrated that the flavonoid fraction of clementine juice provoked induction of several genes and inhibition of both CYP3A4 and CYP1A2, matching effects observed with whole clementine juice. CYP1A2 inhibition and induction can most likely be attributed to nobiletin, sinensetin, and tangeretin. Tangeretin was the only compound causing CYP3A4 induction while CYP3A4 inhibition was most likely the result of additive or synergistic effects caused by several compounds.
Evidence indicates that tangeretin acts through several mechanisms including growth inhibition, induction of apoptosis, autophagy, antiangiogenesis, and estrogenic-like effects. Furthermore, tangeretin works through mitigating levels of inflammatory mediators in the immune system. Available studies suggest that citrus PMFs can exert anticancer activity in six aspects, including reducing tumorigenesis by absorbing environmental carcinogens or eliminating mutations in vivo; promoting apoptosis by regulating apoptotic protein expression; inhibiting cancer cell proliferation or blocking nutrient and oxygen entry into cancer cells during the cell cycle; inhibiting tumor cell invasion or metastasis by suppressing matrix metalloproteinase expression; antagonizing multidrug resistance by inhibiting the activity of the ATP-binding cassette family of membrane transport proteins.
The findings of a preclinical study provide initial evidence indicating that limonene-rich essential oils extracted from Citrus clementina peels offer beneficial effects in mitigating acute lung injury. These effects are primarily attributed to the antioxidant and anti-inflammatory properties of limonene-rich essential oils as well as activating PI3K/AKT signaling pathways.
Clementine fruits have been recognized as a source of innumerable healthy compounds, such as flavonoids and ascorbic acid (vitamin C). Vitamin C is essential for immune competence: supplementation has been associated with improved antioxidant levels, control of inflammatory mediators, and, in some cases, clinical outcomes like disease activity decrease or symptom load. Although findings vary across conditions and few large, randomized trials are available, the overall evidence indicates that maintaining good vitamin C status can be useful in maintaining immune homeostasis and reducing inflammation. The vitamin C evidence base from which clementine's immune-related claims derive is well-established at the nutrient level; data specific to clementine as a whole food are largely observational and extrapolated from general citrus research.
Preclinical studies and clinical trials have demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in cardiovascular diseases. A 2024 systematic review covering literature from PubMed, Scopus, and Web of Science concluded: hesperidin and hesperetin counteract atherosclerosis by ameliorating lipid profiles, inhibiting plaque formation, and reducing inflammation. These flavonoids protect against drug-induced cardiotoxicity. They enhance endothelial function, regulate blood pressure, and counteract oxidative stress.
High intake of beta-cryptoxanthin is reported to be strongly protective against cardiovascular disease (CVD), rheumatoid arthritis, oxidized LDL, inflammation, obesity, and oxidative damage. This carotenoid is important in reduction of cardiovascular risk. High levels of two specific carotenoids, β-cryptoxanthin and lutein, were associated with a decreased risk of acute myocardial infarction among a Chinese cohort of women aged 45–74 years. It must be noted that these findings are primarily from observational and in vitro research; large-scale randomized controlled trials specifically targeting clementine consumption and cardiovascular endpoints are lacking.
Epidemiological studies suggest a potential role of β-cryptoxanthin as a sustainable nutritional approach to improving bone health of human subjects. β-Cryptoxanthin may be an osteogenic factor in preventing osteoporosis in human subjects. β-Cryptoxanthin has stimulatory effects on osteoblastic bone formation and inhibitory effects on osteoclastic bone resorption in vitro, thereby increasing bone mass. β-Cryptoxanthin has an effect on the gene expression of various proteins that are related to osteoblastic bone formation and osteoclastic bone resorption. The intake of β-cryptoxanthin may have a preventive effect on bone loss in animal models for osteoporosis and in healthy human or postmenopausal women. The beneficial effect of β-cryptoxanthin on the risk of osteoporosis and bone fractures was found in the latest meta-analysis from 2021.
In vitro studies showed that citrus flavanones (including hesperidin) exerted antiosteoclastic and anti-inflammatory effects, inhibiting the expression of osteoclastic markers and reducing the levels of reactive oxygen species, proinflammatory cytokines and matrix metalloproteinase levels. Similarly, such studies favored the osteogenic potential of preosteoblastic cells and induced the overexpression of osteogenic markers. In vivo, these flavanones favored the regeneration of bone defects and minimized inflammation in arthritis- and periodontitis-induced models. Additionally, they exerted a significant anticatabolic effect in ovariectomy models, reducing trabecular bone loss and increasing bone mineral density. Although research should advance to the clinical field, these flavanones may have therapeutic potential for controlling the progression of metabolic, autoimmune or inflammatory bone diseases. Evidence strength for bone-related claims remains preliminary to moderate; confirmatory large-scale human RCTs are absent.
Research on clementine-derived PMFs and cancer is substantially in vitro and animal-based. Both nobiletin and tangeretin, isolated from tangerine juice, were shown to be effective inhibitors of human prostate cancer cells and melanoma cells. A more recent study has shown that nobiletin has antiproliferative activity on lung cancer cells both in vitro and in vivo. In this study, nobiletin suppressed proliferation of human lung adenocarcinoma cell line A549 and it had minimal effect on human umbilical vein endothelial cells. It appears that nobiletin induces cell apoptosis, causing cell cycle arrest at the G2/M phase.
Tangeretin inhibited cell proliferation, cancer stem cell (CSC) formation and tumor growth, and modestly induced apoptosis in CSCs. The frequency of a subpopulation with a CSC phenotype (CD44⁺/CD24⁻) was reduced by tangeretin. Tangeretin reduced the total level and phosphorylated nuclear level of signal transducer and activator of transcription 3 (Stat3). Results show that tangeretin inhibits the Stat3 signaling pathway and induces CSC death, indicating that tangeretin may be a potential natural compound that targets breast cancer cells and CSCs.
Several nutrition studies indicate that citrus fruit consumption through the diet is directly linked to a reduced chance of developing certain cancers in the body. Because clementines are fruits equipped with phytonutrients and bioactive compounds that have antioxidant activity, they may exert an anti-cancer effect. However, direct clinical trial evidence for clementine-specific cancer prevention or treatment does not exist; all anti-cancer claims remain at the level of in vitro, animal, and epidemiological data.
Polymethoxyflavonoids such as nobiletin and tangeretin have been reported to exhibit antioxidant, anti-inflammatory, anticancer, and anti-dementia effects, and are also circadian clock modulators through retinoic acid receptor-related orphan receptor (ROR) α/γ. Nobiletin shows various beneficial effects, such as anticancer, anti-inflammation, antioxidation, anti-insulin resistance, antiosteoclastogenesis, immunomodulation, cardiovascular protection, and neuroprotection. These findings are predominantly from animal models and in vitro cell systems; human neurological clinical evidence for clementine or its isolated PMFs is not yet available at sufficient scale.
Research reveals that people who eat citrus fruits on a regular basis are less likely to develop age-related macular degeneration. The flavonoids in citrus fruits may be responsible for this protection. While flavonoids can be found in a variety of fruits and vegetables, the type found in clementines seems to be especially powerful for promoting healthy eyes. This evidence is primarily epidemiological and observational in nature.
Research reports on the chemical composition of clementine essential oil from Algeria, examining its antioxidant and antimicrobial activity against eight spoiling and pathogenic microorganisms. The chemical composition of the essential oils obtained from the peels, by hydrodistillation, was analyzed by GC-MS. Twelve compounds were identified and limonene was the common major component (77–97%). The disc agar diffusion technique indicated clementine essential oil was active against Candida albicans, Escherichia coli, Listeria innocua, and methicillin-resistant Staphylococcus aureus. This represents in vitro antimicrobial data only; no clinical trials exist for clementine EO as an antimicrobial agent in humans.
A study aimed to provide insights into the anti-inflammatory effect of limonene-rich essential oils extracted from C. clementina using two distinct delivery systems, oral and inhalation routes, in potassium dichromate-induced acute lung injury (ALI), focusing on the PI3K/AKT signaling pathway in rats. CCEO (clementine cold-expressed essential oil) at doses of 100 and 200 mg/kg body weight exhibited antioxidant and anti-inflammatory properties in this animal model. This is animal-based evidence only.
As a whole fruit, clementines are consumed in quantities of one to several fruits per day in dietary and epidemiological contexts; no standardized therapeutic dose for the fruit as a supplement has been established by pharmacopeias or regulatory bodies.
In the most directly relevant human study on drug interactions, an increment of 43% in the estimated midazolam clearance was observed during the first experiment in a renal transplant patient on tacrolimus after 4-day consumption of clementines (1 kg/day), and an increment of +89% was observed during chronic consumption of clementine juice in a healthy male volunteer.
For isolated constituents studied in animal models: clementine essential oil (CCEO) at doses of 100 and 200 mg/kg body weight exhibited antioxidant and anti-inflammatory properties in rat models of acute lung injury. In vivo imaging showed that the PER2::LUC rhythm in peripheral organs was altered in accordance with the timing of nobiletin administration (100 mg/kg) in mice. These figures are from animal studies and cannot be directly extrapolated to human clinical dosing.
For hesperidin specifically, a range of preclinical studies and clinical trials have been conducted, demonstrating therapeutical effects in neurological, psychiatric, and cardiovascular diseases due to its anti-inflammatory, antioxidant, lipid-lowering, and insulin-sensitizing properties; dosages for such trials vary by condition and formulation and are described in disease-specific hesperidin literature rather than in clementine-specific supplement protocols.
Data indicate that clementine juice, similar to grapefruit juice, bears the potential for profound interactions with drugs, potentially leading to adverse drug effects, e.g., through over-exposure to CYP3A4 substrates. This was established by in vitro work at the University of Heidelberg, which demonstrated: substantially increased tacrolimus trough concentrations in a renal transplant patient consuming high clementine amounts; scrutiny of the effects of clementine juice on drug metabolism and drug transporters in vitro showed all citrus juices profoundly induced several drug transporters and drug metabolising enzymes, with clementine juice causing a 34-fold induction of CYP3A4 mRNA.
However, clinical translation remains uncertain. A follow-up single-case experiment found: although an increment of 43% in the estimated midazolam clearance was observed during 4-day consumption of clementines (1 kg/day), and an increment of +89% was observed during chronic consumption of clementine juice in a healthy male volunteer, these changes lie within the range of intra-individual variability. Therefore one cannot assure a potential drug interaction due to clementines, but prescribers should be cautious unless further data emerges.
Given that clementines do not contain furanocoumarins (bergamottin, dihydroxybergamottin, or epoxybergamottin), which are established CYP3A4 inhibitors responsible for most clinically relevant food-drug interactions with grapefruit juice, and the primary clementine compounds, hesperidin and narirutin, are not known to be strong inducers or inhibitors of CYP3A4 and CYP1A2, identification of the compounds responsible is necessary. CYP1A2 inhibition and induction can most likely be attributed to nobiletin, sinensetin, and tangeretin. Tangeretin was the only compound causing CYP3A4 induction while CYP3A4 inhibition was most likely the result of additive or synergistic effects caused by several compounds.
Whenever evaluating the clinical relevance of clementine interactions, flavonoid contents should be reported because these might explain differences between cultivars and harvests.
An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. Tacrolimus is metabolized in the liver, involving the CYP3A4 isoform, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability.
Clementines contain citric acid and are acidic in nature. They are typically juicy and sweet, with less acid than oranges. Despite their comparatively lower acidity relative to oranges, individuals with gastroesophageal conditions may experience discomfort. No specific clinical data on clementine-induced gastrointestinal adverse events in sensitive populations have been published in reviewed literature.
Clementines do not contain furanocoumarins (bergamottin, dihydroxybergamottin, or epoxybergamottin). This distinguishes them from grapefruit and bergamot in terms of phototoxicity risk; the absence of furanocoumarins means that the photodermatitis concerns associated with some other citrus species are not applicable to clementine.
No formal toxicological assessments, no-observed-adverse-effect level (NOAEL) studies, or specific safety monographs have been issued by major bodies (WHO, EFSA, EMA, or US Pharmacopeia) specifically for clementine as a supplement ingredient, reflecting its status primarily as a commonly consumed food fruit rather than a pharmaceutical agent or regulated dietary supplement. The safety of clementine consumed as a food is well-established by its long history of dietary use; safety considerations become relevant primarily in the context of very high, concentrated, or extract-based consumption, particularly in combination with CYP3A4-metabolized medications.
Health conditions that Clementine may help support.
Body systems that Clementine may help support.
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