Lycopene

This page as PDF · Summary

1. What Lycopene Is

Lycopene is a carotenoid, a fat-soluble plant pigment found in tomatoes and other carotenoid-rich vegetables. Within this group it occupies a special position: unlike β-carotene, it is not a precursor of vitamin A. These forms address different questions and are kept separate here. β-carotene, lutein and zeaxanthin are also covered within the same substance group, each with its own endpoints, for example at the eye. Part of the literature originates from agricultural and environmental research and does not concern human application.

For the appraisal of all studies it is decisive how lycopene is absorbed and measured. Intake is estimated via dietary questionnaires or captured as blood levels; both routes record different things. The Framingham analysis refers to total carotenoid intake, not to lycopene alone. Added to this is the diversity of forms: isolated supplements, Lactolycopene, lycopene-enriched ice cream, carotenoid-rich vegetables and lycopene as an add-on to ongoing treatment have all been tested. Plausible: That absorption differs according to matrix is already suggested by the fact that bioavailability is pursued as a separate research field. The predominant endpoints are markers in blood or seminal plasma, less often clinical endpoints.

2. How Robust the Research Is

Research is distributed unevenly. Animal studies and basic-research papers form the largest group, followed by cell-culture work and studies on human cells as well as a block of environmental and agricultural investigations. In humans, observational studies predominate; controlled studies exist but are clearly in the minority. Content-wise, antioxidant questions dominate, followed by metabolism, fatigue, safety and oncology. Cardiovascular, inflammation, immune system, bioavailability and skin appear with single studies. The emphasis therefore lies on oxidative status and metabolic markers, not on disease courses.

The methodological spectrum is broad. Randomised, double-blind, placebo-controlled studies stand alongside small pilot studies, observational cohorts and mechanistic reviews. Proven: For statements about humans the controlled studies carry the main weight. Several of them test lycopene against another substance rather than against placebo or as an add-on to ongoing treatment; a between-group difference can then be shown, yet cannot readily be attributed to lycopene. Other studies form part of larger cohorts with a broader scope, for example on total carotenoid intake. Mechanistic and preclinical work predominates in oncology. What must be clarified first is the contribution of the single substance in a design that tests it alone.

Distribution of controlled human studies by application area — the figures are not additive, as one study may be assigned to several areas:

3. What Is Frequently Claimed — and What the Data Support

4. Profile: Molecule and Charge

Lycopene is not a single molecule but a mixture — there is no molecular formula and no fixed molecular mass. What can be described are functional groups, charge behaviour and redox properties; this is exactly what the next section addresses.

5. Charge, Electrons, Radicals

A measurement on charge and cation exchange is still outstanding. Electron transfer is described as radical scavenging: carotenoids such as β-carotene, lycopene, lutein and zeaxanthin can neutralise reactive oxygen species and mitigate oxidative stress 27; radical scavengers act via quenching and neutralisation 25. In a preclinical trial, 20 mg/kg lycopene reduced malondialdehyde and reactive oxygen species while catalase, superoxide dismutase and glutathione peroxidase increased; serum BUN, creatinine and cystatin C decreased 24. In cells, pretreatment with three nutrients lowered ROS by 1.7- to 2.2-fold and intracellular MDA by 33.87 % to 40.10 % 26.

Little has been measured in humans so far. A randomised clinical study examined how lycopene modulates oxidative stress and liver enzyme values in patients with metabolic syndrome 23. Oral supplementation with carotenoids recorded plasma levels as well as visual and skin attributes 25. Direct measurements of charge, cation exchange or electron transfer in humans are not included. It remains open to what extent the radical neutralisation described preclinically becomes measurable in humans; what would need to be clarified is which redox parameters a human study should capture.

6. Interactions with Other Substances

With which other substances on the platform this substance is jointly investigated or discussed in human studies and reviews — combination, comparison or shared mechanism of action. The number indicates studies in which both occur.

Lycopene tablets achieved a healing rate of 63 % in oral leukoplakia, and 72 % of participants were healed after the combination of curcumin and lycopene 28. Docetaxel with lycopene was investigated in a small sample; the authors consider the combination worthy of further examination 20. Sorafenib with lycopene inhibited the proteins Bcl-2, Ki-67, VEGF, IL-1β and TNF-α in a human observation 31. For SMZ, human observations describe that coadministration of lycopene restored cytochrome P450-1A1 homeostasis, reduced intracellular ROS accumulation and normalised immune and apoptosis markers 30, 30.

Two controlled human studies showed that black pepper with an emulsion based on vegetable oil or canola oil synergistically increased the carotenoid bioavailability of raw vegetables 29, 29. A review article addresses synergism and delivery systems of lycopene 32. It remains to be clarified whether the uptake effects also apply to lycopene itself.

7. Overdosage, Tolerability, Limits

These sentences do not contain quantity information on lycopene.

The contraindication there concerns dexamethasone, not lycopene. Preclinical animal studies and clinical studies are used for the safety of carotenoids 33. A dose at which adverse effects occur, a tolerable daily dose or a limit for intake cannot be derived from this. A dose-finding study in humans that systematically records adverse events and at the same time measures the plasma levels of the carotenoids would need to be clarified 18.

8. The Most Robust Studies

Ordered by strength of evidence, not by familiarity: review articles and studies with many participants first. The complete evaluation comprises significantly more studies; the most robust ones are listed here.

Controlled Human Studies

• 1 Efficacy of lycopene in management of Oral Submucous Fibrosis- A systematic review and meta-analysis (2020) — Übersichtsarbeit, 1.181 Teilnehmer
• 2 Dietary and Nutraceutical Interventions as an Adjunct to Non-Surgical Periodontal Therapy-A Systematic Review (2023) — Übersichtsarbeit
• 3 Systematic review and meta-analysis of the antioxidant capacity of lycopene in the treatment of periodontal disease (2023) — Übersichtsarbeit
• 4 Effectiveness of non-pharmaceutical intervention on sperm quality: a systematic review and network meta-analysis (2023) — Übersichtsarbeit
• 5 The effect of lycopene supplement from different sources on prostate specific antigen (PSA): A systematic review and meta-analysis of randomized … (2022) — Übersichtsarbeit
• 6 Lycopene Does Not Affect Prostate-Specific Antigen in Men with Non-Metastatic Prostate Cancer: A Systematic Review and Meta-Analysis of Randomized … (2021) — Übersichtsarbeit
• 7 Effects of Lycopene Supplementation on Bone Tissue: A Systematic Review of Clinical and Preclinical Evidence (2025) — Übersichtsarbeit
• 8 Effect of Intake of Lycopene-Containing Products on Vascular Endothelial Function in Healthy Adults: A Systematic Review with Meta-Analysis (2026) — Übersichtsarbeit
• 9 Total carotenoid intake is associated with reduced loss of grip strength and gait speed over time in adults: The Framingham Offspring Study (2021) — 2.452 Teilnehmer
• 10 Association between Circulating Antioxidants and Longevity: Insight from Mendelian Randomization Study (2022) — 1.012.240 Teilnehmer
• Phase II randomised control feasibility trial of a nutrition and physical activity intervention after radical prostatectomy for prostate cancer (2019) — 108 Teilnehmer
• 11 Effect of green tea and lycopene on the insulin-like growth factor system: the ProDiet randomized controlled trial (2019) — 133 Teilnehmer
• 12 Cardiovascular and Osteoporosis Protection at Menopause with Lycopene: A Placebo-Controlled Double-Blind Randomized Clinical Trial (2022) — 100 Teilnehmer
• 13 Comparison of therapeutic response of lycopene and curcumin in oral submucous fibrosis: A randomized controlled trial (2019) — 30 Teilnehmer
• 14 A comparative study to evaluate the efficacy of lycopene and curcumin in oral submucous fibrosis patients: A randomized clinical trial (2018)
• 15 Antioxidant therapy in idiopathic oligoasthenoteratozoospermia (2017)
• 16 The effects of lycopene supplement on the spermatogram and seminal oxidative stress in infertile men: A randomized, double-blind, placebo-controlled … (2019)
• 17 A randomized placebo-controlled trial to investigate the effect of lactolycopene on semen quality in healthy males (2020)
• 18 Dietary Intake of Carotenoid-Rich Vegetables Reduces Visceral Adiposity in Obese Japanese men-A Randomized, Double-Blind Trial (2020)
• 19 Systemic and skin-targeting beneficial effects of lycopene-enriched ice cream: A pilot study (2019)
• 20 A phase II study of docetaxel plus lycopene in metastatic castrate resistant prostate cancer (2021) — 10 participants
• 21 Investigating Causal Associations of Diet-Derived Circulating Antioxidants with the Risk of Digestive System Cancers: A Mendelian Randomization Study (2022)
• Natural products for the management of xerostomia: a randomized, double-blinded, placebo-controlled clinical trial (2017) — 60 participants
• 22 Serum 8-isoprostane levels in patients with resistant oral lichen planus before and after treatment with lycopene: a randomized clinical trial (2021)

9. Summary

They are, however, clearly in the minority; observational studies predominate in humans, while animal and basic research constitute the largest group in the overall literature. Several controlled studies test lycopene against another substance rather than against placebo or as an add-on to ongoing treatment; a difference between the groups can then be demonstrated, but not readily attributed to lycopene. Attribution to the single substance remains the open flank of this literature.

Isolated supplements, lycopene-enriched ice cream, carotenoid-rich vegetables and lycopene as an add-on to ongoing treatment were examined. Hypothesis: Where an effect appears, it shows first in markers in blood or seminal plasma, because the placebo-controlled studies measure semen parameters and markers, not the birth of a child. Whether such a marker finding is reflected in the clinical course remains open.

The first point to clarify would be the contribution of the single substance in a design that tests it alone: a randomised, placebo-controlled study that compares lycopene as a pure substance against placebo and records a clinical endpoint rather than a marker. It is also open how strongly blood levels after supplements, enriched foods and estimates from dietary questionnaires differ from one another. The Framingham study links total carotenoid intake with muscle strength and gait speed; what share lycopene has in this remains a testable question. For tolerability, a dose-finding study in humans would be required that systematically records adverse events while simultaneously measuring plasma levels of the carotenoids.

10. What Remains Open

• Pure Substance: Which randomised, placebo-controlled study tests lycopene alone and records a clinical endpoint rather than a marker?
• Absorption: How strongly do blood levels after supplements, enriched foods and estimates from dietary questionnaires differ from one another?
• Carotenoids Overall: The Framingham study links total carotenoid intake with muscle strength and gait speed. What share does lycopene have in this?

11. Further Paths

Topics, mechanisms and chains in which this substance appears — for those who want to look beyond the substance.

• Interaction Network

Topics, pathways and chains in which this substance occurs — for all who wish to look beyond the substance.