Evaluating the Clinical Evidence for: Ginger, Green Tea, and St. John’s Wort: A Botanical Review
Kennedy Dove, Gabriella Hogg, Maria Marwat, and Angelina Stankovic
Undergraduate Students, University of Guelph
Introduction
Plants have always been a staple in fortifying human health, not only as nourishment, but also for medicinal and holistic support. Ancient civilizations recognized plants’ intrinsic properties and cultivated specific species for the prevention of illness, for symptom alleviation and for the promotion of physical and emotional well-being. Current interest in integrative practices has fostered scientific curiosity for their therapeutic potential, placing alternative medicine as a sought-after complement. As a result, clinical trials have begun to assess commonly used botanicals, specifically, ginger, green tea and St. John’s Wort. These are respectively used for nausea relief, cancer prevention and as a treatment for depression. This paper will review this clinical research and their tangible contributions beyond traditional claims. Variables such as harvesting protocols and sample preparations will be considered, as they are integral for replicable experiments and authentic results. The plant’s key bioactive metabolite can only be quantified via consistent testing. This will validate the demand for future studies, illuminating the role of these plants’ benefits in human health.
Ginger (Zingiber officinale Roscoe)
Ginger (Zingiber officinale Roscoe) is a perennial tropical herbaceous plant that grows 3 to 4 feet tall from an underground rhizome (Ramdin, 2023). Ginger has long, fragrant lanceolate-shaped leaves that grow from long stems. The flowers are a yellowish white that grow in a group from the end of a spike. The rhizome or root of ginger is what most people as the spicy-sweet ingredient that seasons food and drinks (Ramdin, 2023). Ginger has a long history of being used as a medicinal herb, both in Ayurvedic medicine and traditional Chinese medicine. It was not only used as a digestive aid but was also prescribed for nausea, inflammation, and as an aphrodisiac. Ginger has a rich cultural history, particularly in 500–300 BCE China, where the Chinese philosopher Confucian prescribed ginger with every meal to aid in digestion (Ramdin, 2023). Today, ginger is still studied for its anti-nausea and anti-vomiting effects, especially for motion sickness, pregnancy and chemotherapy. It’s also being studied for its anti-inflammatory effects, especially for treating inflammatory bowel disease (Mao et al., 2019).
Image 1: Ginger rhizome with stem and leaves still attached (Veronicatxoxo, 2019)
Ginger’s Mechanism of Action
Ginger contains many medicinal compounds such as gingerols, shogaols, and paradols. Fresh ginger mainly contains gingerols such as 6-gingerol, 8-gingerol, and 10-gingerol, which are polyphenols (Mao et al., 2019). When ginger is dried, the gingerols become their shogaol counterparts 6-shogaol, 8-shogaol, and 10-shogaol. Ginger is known to have anti-inflammatory properties, which work by inhibiting inflammatory signalling pathways, such as Akt and NF-kB (Mao et al., 2019). Ginger decreases levels of proinflammatory cytokines such as TNF-α, IL-6, and IL-1β while increasing the levels of anti-inflammatory cytokines such as IL-10 and IL-22. These are signalling molecules produced by the immune system to regulate inflammation (Mao et al., 2019). Ginger is also known for its anti-nausea and vomiting properties, which are due to 6-Shogaol and 6-gingerol inhibiting 5-HT serotonin receptors in enteric neurons and vagal afferent neurons. These neurons are responsible for inducing nausea and vomiting (Mao et al., 2019).
Clinical Trial on Ginger and Nausea
Nausea and vomiting are common symptoms in early pregnancy, reported to affect around 90% of pregnant women (Amjadi et al., 2025). These symptoms often appear at around week six, peaking at week 12, and subsiding by week 20. The exact cause of these symptoms is still unknown, but it seems to be related to elevated hormones due to pregnancy, along with physical and environmental factors. Given its prevalence and the unnecessary stress it can cause to the mother and therefore the fetus, a need for safe and effective treatment is necessary (Amjadi et al., 2025). Today, the most common medication given for nausea and vomiting during pregnancy is Ondansetron. Ondansetron is a serotonin antagonist, which blocks the action of serotonin, a neurotransmitter that can trigger nausea and vomiting. Although Ondansetron is safe to use during pregnancy, many women still avoid using it due to the side effects, alongside the fear that it may harm the pregnancy (Amjadi et al., 2025). Ginger is a natural herb used to treat nausea and vomiting and is considered safe for pregnancy. Given the fear of taking synthetic medication during pregnancy and the prevalence of nausea and vomiting, other options should be available that are equally effective and safe. Amjadi et al (2025) ran a triple-blind clinical trial on 40 pregnant women visiting a perinatal clinic. The study aimed to find out if ginger would be just as effective as Ondansetron in treating nausea and vomiting.
The trial was run in Shohadaye Tajrish Hospital, with the approval from the Research Deputy of Pharmaceutical Sciences Research Center of Shahid Beheshti University of Medical Sciences, along with authorization from the Ethics Committee. As with most clinical trials, they had inclusionary and exclusionary criteria to ensure safety and the accuracy of the trial. To be a part of the trial, women must be between 6 and 16 weeks of gestation, experiencing mild to moderate nausea and vomiting, and carrying a singleton. Moreover, participants could not have any sensitivity to ginger or Ondansetron, nor be taking any anticoagulant medications, and not have any underlying illnesses (Amjadi et al., 2025).
Identical capsules were created with either 8 milligrams of Ondansetron powder produced by Tehran Chemi Company or 500 milligrams of ginger root powder obtained from the market in Tehran in 2021. They were packaged in a set of 12 capsules. Due to the triple blind nature of the study, neither the participants, researchers, nor statisticians knew who was given which medication. The participants were instructed to take one capsule every 12 hours for 4 days. They recorded their symptoms every 12 hours using the Rhodes questionnaire. The questionnaire contained 8 questions, ranging from the number of times they experienced vomiting, nausea or retching to how much distress was caused by these events. A Shapiro-Wilk test was used to assess the normality of variables, and an independent t-test was used to assess the groups before the medication. An ANCOVA was used to compare the groups after medication (Amjadi et al., 2025).
Table 1. Mean and standard deviation of the combined score for vomiting, nausea, and retching for both ginger and Ondansetron before and after the medication (Amjadi et al., 2025).
Results and Discussion
They found no statistical difference in the vomiting, nausea or retching scores for the 2 groups before medication, along with finding no statistically significant difference between the groups after medication. The test showed that there was a statistical difference in the vomiting, nausea or retching scores for both groups before and after medication, highlighting a decrease in symptoms. The trial showed that ginger is just as effective at treating pregnancy-related nausea and vomiting as Ondansetron, suggesting it can be a comparable alternative. Other studies done on ginger show that it is effective in reducing nausea and vomiting in placebo trials. There have even been other trials done comparing ginger to other anti-nausea medications like Metoclopramide and vitamin B6 to show their effectiveness (Amjadi et al., 2025). Differences in these trials can be attributed to different designs, dosages and mechanisms of action. Metoclopramide affects gut motility and dopamine, Ondansetron blocks serotonin, while ginger works on anti-inflammatory and anti-nausea pathways. There is a concern with ginger dosing, as it can affect cardiac, diabetic, and anticoagulant medications (Amjadi et al., 2025). This study, in conjunction with others, suggests that ginger can be a safe option in treating nausea and vomiting related to pregnancy. Whether ginger is taken independently or in combination with other anti-nausea medications can help target multiple pathways for increased relief.
Green Tea (Camellia sinensis)
Green tea (Camellia sinensis) is a perennial evergreen shrub that can grow 2-5 meters in height. It is well known for its dark, shiny leaves and small, white, fragrant flowers. The leaves specifically give rise to the famous beverage (Huda et al., 2024). Green tea originated around 2700 B.C in ancient China, where it was used medicinally (Huda et al., 2024). Green tea’s discovery was accidental when the Chinese Emperor Shennong drank boiled water containing the plant’s leaves. However, it was not until the 14th century that green tea became accessible to the general public (Huda et al., 2024). As a result, green tea has become one of the most extensively studied natural products. Recently, the botanical’s role in cancer research has grown in demand due to its high catechin content. Epigallocatechin-3-gallate (EGCG) has been shown to interfere with multiple biological processes involved in carcinogenesis. EGCG is known for its safety, low cost and cultural acceptance, making it a possible long-term cancer-preventive strategy (Li et al., 2014). Unlike synthetic chemopreventive drugs, green tea is consumed daily worldwide. This allows for sustained exposure to its bioactive compounds without the toxicity concerns associated with pharmaceuticals. Green tea, with its combination of safety and biochemical potency, positions itself among the most intriguing natural agents being studied for cancer prevention.
Green Tea’s Mechanism of Action
Green tea is a blend of many different polyphenolic compounds referred to as catechins. The most notable catechins in green tea are: epigallocatechin-3-gallate (EGCG), epicatechin-3-gallate (ECG), epigallocatechin (EGC) and epicatechin (EC), which are all present in high concentrations (Radeva-Ilieva et al., 2025). Specifically, EGCG is the most predominant catechin in tea leaves. EGCG works by modulating key signalling pathways that play a role in cancer development (Dou, 2009). For example, EGCG can inhibit the activation of NF-kB, a transcription factor that mediates the expression of inflammatory genes. When proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukins (IL-1, IL-6, IL-8) are sequestered, there is decreased inflammation, reducing pain and tissue damage (Radeva-Ilieva et al., 2025). Moreover, ECGC is believed to have antioxidant properties, including cell cycle regulation, apoptosis induction, and regulates not only protein expression but also enzymatic activity (Dou, 2009). This is especially helpful to prevent cancer cells, which utilize oxidative stress for their survival. Collectively, the above-mentioned mechanisms stimulate normal physiological function, contributing to cancer prevention.
Currently, cancer treatment strategies have used green tea as a complement to standard chemotherapies. Green tea’s well-characterized phenolic compounds can enhance anticarcinogen efficacy by 10-15 times, compared to independent use (Cao et al., 2016). This enhancement has been observed with Bleomycin, a frequently used chemotherapy; however, cancer cells have become increasingly resistant to it. When Bleomycin was used with green tea, its cytotoxic effects were restored, counteracting the resistance (Cao et al., 2016). Furthermore, Tamoxifen is another chemotherapy drug used in breast cancer. Tamoxifen functions as an estrogen-receptor antagonist within cancer cells, preventing their growth (Cao et al., 2016). Green tea is often a supplemental treatment as it increases Tamoxifen’s inhibitory effects, leading to higher levels of apoptosis among cancer cells (Li et al., 2014). Together, these findings convey the therapeutic potential of green tea as a valuable adjuvant to current cancer therapies.
Clinical Trial of Green Tea and Breast Cancer
Clinical and experimental findings suggest that green tea catechins, particularly EGCG, may have anticancer properties in the prevention and treatment of breast cancer. A Phase Ib randomized, double-blind, placebo-controlled trial was conducted to evaluate the safety and biological effects of Polyphenon E, an EGCG-rich extract, in women with resected stage I–III ER-/PR breast cancer (Crew et al. 2012). Women from 4 sites in the USA, ranging from 21 to 65, participated in the study. They were asked to abstain from any tea consumption before and during the trial and to reduce caffeine consumption. The participants were split into three groups that took either 400mg, 600mg, 800mg or a placebo of EGCG capsules twice a day for 6 months. The toxicity of the dose was monitored with lab work every 2 weeks for the first month, then once a month for the remainder of the study. They also looked at the biological effects of EGCG by doing mammograms, random core biopsy, and comparing blood serum hormone levels at baseline and after 6 months. They also assessed the presence of tea catechins metabolites in urine samples every 2 months using high-performance liquid chromatography. They used a Wilcoxon signed-rank test to look at between-group and within-group differences in the variable, along with running a repeated-measure ANOVA to look at continuous data between groups. Researchers found that doses of up to 600 mg EGCG twice daily were well tolerated, establishing the maximum tolerated dose. Greater doses resulted in acceptable toxicities.
Results and Discussion
While the study found reductions in blood estradiol and SHBG in the treatment groups, these changes were not much different from the placebo, and no changes in breast tissue proliferation indicators were seen after the six-month intervention. In addition to these findings, EGCG provided with radiotherapy, dramatically lowered circulating VEGF, HGF, and active MMP-2/-9 levels, implying that EGCG may improve radiation therapy by reducing angiogenesis and tumour-promoting pathways (Crew et al. 2012). Preclinical animal data show that EGCG delays tumour onset, reduces tumour size and number, promotes apoptosis, suppresses angiogenic and inflammatory signalling (including HIF-1α, NF-kB, and VEGF), and improves responses to therapies like Tamoxifen and Paclitaxel (Li et al., 2014). Together, the human trials and animal research demonstrate EGCG’s promise as a safe, physiologically active chemical that may reduce tumour progression and improve therapy results, giving a strong case for larger-scale clinical trials.
Table 2. Means for secondary biomarker for both Poly E and placebo participants at baseline and endpoint (Crew et al. 2012)
Overall, the clinical and preclinical evidence presented strongly supports green tea’s role as a promising natural agent in cancer prevention. Its ability to delay cancer onset, reduce tumour growth in early-stage patients, and interfere with fundamental carcinogenic processes highlights both its preventive and therapeutic ability. As a widely consumed, low-toxicity beverage, green tea offers a practical, accessible way to reduce cancer risk and support long-term health. Future controlled clinical trials will help clarify optimal consumption levels and determine which patients are most likely to benefit. Still, existing data have already highlighted green tea’s significant potential in holistic cancer prevention.
St. John’s Wort (Hypericum perforatum)
St. John’s Wort (Hypericum perforatum) is a perennial herb belonging to the Clusiaceae family. The plant can reach 40 to 80 cm in height and has branches covered with leaves varying from 1 to 3 cm long. The plant also produces small, star-shaped yellow flowers, which are the main source of its medicinal compounds (Klemow, 2011). St. John’s Wort has been used for centuries in traditional medicine and has been incorporated into Western medicine as well. Modern research on the plant focuses on the effects of its active compounds, which include hypericin and hyperforin (Klemow, 2011). These compounds can help with many things, including depression. Depression is a common mood disorder that negatively affects an individual’s overall feelings, sleeping, energy levels, concentration, appetite, and can cause serious thoughts of death (Onyemaechi, 2024). Due to the number of individuals who have depression, and its severe impacts, effective treatments are needed. For this reason, a clinical trial investigating the effectiveness of St. John’s Wort in reducing the severity of symptoms of depression was reviewed.
St. John’s wort has been used for its medicinal properties for over 2000 years. It has been recommended by ancient Greek physicians such as Galen, Dioscorides, Pliny, and Hippocrates to treat wounds, snake bites, and menstrual issues (Klemow, 2011). It was believed that St. John’s Wort could ward off evil spirits. Moreover, if harvested on June 24, also known as St. John’s Day, the plant would have greater medicinal benefits (Touwaide & Appetite, 2023). Sixteenth-century herbalists like Paracelsus, Gerard, and Culpeper also recommended St. John’s Wort to treat wounds and alleviate pain, and it was also recommended for treating depression in the year 1525 (Klemow, 2011).
Pharmaceutical Preparations
There are multiple different forms of St. John’s Wort that are used medicinally, including oils, teas, capsules, tablets and more (Mayo Clinic, 2025). St. John’s Wort is produced by grinding down the plant’s dried flowers and leaves (Peterson, 2023). Clinically, St. John’s Wort is prepared as an extract in capsule form. The capsules have different amounts of hypericin and hyperforin. For example, LI 160 contains 0.3% hypericin and 1-4% hyperforin, whereas Ze 117 has lower hypericin. Another example is WS 5570, which is an 80% ethanol extract of St. John’s Wort that includes 5-6% of hyperforin and about 0.28% of hypericin (Klemow, 2011).
St. John’s Wort Mechanism of Action
St. John’s Wort contains several different groups of medicinally active compounds. The most common classes are naphthodianthrones, phloroglucinols, and flavonoids (Klemow, 2011). Among these, the two main medicinally active compounds are hypericin and hyperforin, which contribute most to the plant’s therapeutic effects. Hypericin, a naphthodianthrone, is found in the plant’s flowers and reacts strongly to light because hydrogen atoms are able to shift between nearby oxygen atoms. When exposed to light, the hydrogen movement also increases the acidity of its surroundings (Klemow, 2011). Additionally, hyperforin is a major phloroglucinol in St. John’s Wort and is a lipophilic compound. When exposed to light and oxygen, hyperforin is unstable, which is why it has not been fully synthesized yet. Phloroglucinols like adhyperforin and furohyperforin are also found in St. John’s Wort and are able to improve extract stability and can assist with hyperforin’s antidepressant effects (Klemow, 2011). Flavonoids are another important group of compounds in St. John’s Wort and are found in the stems, flowers, and leaves of the plant. Flavonols, flavones, glycosides, and biflavones have antioxidant, anti-inflammatory and neuroactive properties, which all contribute to St. John’s Wort’s mood-regulating ability (Klemow, 2011). Overall, hyperforin, hypericin, and the plant’s flavonoids are able to regulate neurotransmitters like serotonin and dopamine and are believed to be the main compounds responsible for St. John’s Wort’s antidepressant effects (Klemow, 2011).
Clinical Trial of St. John’s Wort and Depression
To evaluate the effectiveness of St. John’s Wort in treating individuals with depression, a double-blind, placebo-controlled clinical trial was conducted. A study by Kasper et al. was able to look at the safety and effectiveness of the St. John’s Wort extract WS 5570 in patients with mild to moderate depression. The researchers hypothesize that WS 5570 is more effective than the placebo in reducing the symptoms and severity of depression and that WS 5570 would result in a lower Hamilton depression scale score. The trials lasted for 6 weeks and included individuals who were 18 to 65 years old who had mild to moderate depression according to the Hamilton depression Scale (score less than 18). Patients were assigned to groups that either received a placebo, 600 mg of WS 5570/day, or 1200 mg of WS 5570/day. There were a total of 324 patients, with 81 being in the placebo group, 119 in the 600 mg/day WS 5570 group, and 124 in the 1200 mg/day WS 5570 group. Data was collected from 2003 to 2004, where efficiency for both groups was measured in relation to the patients’ changes in their Hamilton Depression Scale scores. Responder and remission rates were also taken into account. Additionally, the researchers used adaptive interim analysis to determine significance (Kasper et al. 2006).
Figure 1. Change in mean depression score across all groups in relation to the day of treatment (total of 42 days). The three treatment groups included two St. John’s Wort groups (WS 5570 600 mg/day, n=124; WS 5570 1200 mg/day, n=119) and the placebo group (n=81). Both groups taking St. John’s Wort showed a faster and greater reduction in Hamilton Depression scores when compared to the placebo group (Kasper, 2006).
Results and Discussion
The results showed, the patients who were treated with WS 5570 had a much larger reduction in their Hamilton depression scores compared to the individuals in the placebo group. The 600 mg/day St. John’s Wort group had a mean decrease of 11.6, and the 1200 mg/day St. John’s Wort group had an average decrease of 10.8. On the other hand, the placebo group only had an average decrease of 6 in Hamilton depression scores. Responder rates were significantly higher amongst the individuals in the WS 5570 group (600 mg/day = 70%; 1200 mg/day = 61%) when compared to the placebo group’s rates (32%). Responders were identified as any individual who had a reduction of 50% or more in their depression scores. Individuals with higher Hamilton depression scores at the beginning of the trials showed greater effects of St. John’s Wort (Kasper et al. 2006). Overall, the results show St. John’s Wort is more effective in treating symptoms of depression when compared to a placebo. A greater decrease in the WS 5570 groups’ Hamilton scores indicated this, as well as the greater responder and remission measured for the group. These findings suggest St. John’s Wort is a viable herbal treatment for reducing the symptoms associated with depression (Kasper et al. 2006).
Conclusion
In conclusion, among the three botanicals reviewed– ginger, green tea and St. John’s Wort– one central theme emerges: science is reinforcing traditional practices. For centuries, these plants have been valued for their medicinal properties, yet only through modern medicine can their mechanism and safety be evaluated. Each of the clinical trials highlights the plant’s key bioactive compound, confirming many of their long-standing uses. For example, 6-gingerol and 6-shogaol give credence to ginger’s anti-nausea and anti-inflammatory properties. As discussed, these compounds were able to reduce pregnancy-related nausea at comparable levels to standard pharmaceuticals. Similarly, the EGCG catechin found in green tea is capable of interacting with carcinogenic molecular pathways. This demonstrates how green tea can be used in conjunction with chemotherapies or taken as a preventative measure. Lastly, St. John’s Wort, with its hypericin and hyperforin compounds, was shown to ease symptoms of depression and can be comparable to conventional antidepressants.
While these findings confirm the therapeutic potential of these botanicals, they also highlight the importance of consistent research practices. Differences in plant harvesting, preparation methods and dosing can severely impact the concentration of bioactive compounds, thereby affecting clinical outcomes. Due to this, standardization of protocols is essential for ensuring the reliable use of holistic medicines in modern settings. Furthermore, safety considerations, such as how botanics interact with prescription drugs, must be carefully assessed to ensure patient well-being. These variables demonstrate that although traditional practices provide valuable insight, they require scientific evaluation to establish their efficacy, potency and safety.
Overall, the blend of historical knowledge and modern research showcases botanic’s complementary role in healthcare. Botanics are not intended to replace conventional treatments, but to offer accessible options to enhance therapeutic outcomes. By bridging tradition with clinical investigation, ginger, green tea and St. John’s Wort exemplify how natural products can be integrated into modern medicine. Continued research regarding large-scale clinical trials will be necessary to determine appropriate dosing, long-term effects, and identify ideal patient populations most likely to benefit from traditional remedies.
References:
Amjadi, M. A., Mojab, F., Masjoudi, M., Afrakheth, M., Farahani, M. F. (2025). Comparing the Effect of Ondansetron and Ginger on Pregnancy-Related Nausea and Vomiting in Women Attending the Perinatal Clinic in Tehran(A Randomized Clinical Trial). Research Square. https://doi.org/10.21203/rs.3.rs-4965993/v1
Cao, J., Han, J., Xiao, H., Qiao, J., & Han, M. (2016). Effect of Tea Polyphenol Compounds on Anticancer Drugs in Terms of Anti-Tumor Activity, Toxicology, and Pharmacokinetics. Nutrients, 8(12), 762. https://doi.org/10.3390/nu8120762
Crew, K. D., Brown, P., Greenlee, H., Bevers, T. B., Arun, B., Hudis, C., McArthur, H. L., Chang, J., Rimawi, M., Vornik, L., Cornelison, T. L., Wang, A., Hibshoosh, H., Ahmed, A., Terry, M. B., Santella, R. M., Lippman, S. M., & Hershman, D. L. (2012). Phase IB randomized, double-blinded, placebo-controlled, dose escalation study of polyphenon E in women with hormone receptor-negative breast cancer. Cancer Prevention Research (Philadelphia, Pa.), 5(9), 1144–1154. https://doi.org/10.1158/1940-6207.CAPR-12-0117
Dou, Q. P. (2009). Molecular Mechanisms of Green Tea Polyphenols. Nutrition and Cancer, 61(6), 827–835. https://doi.org/10.1080/01635580903285049
Huda, H., Majid, A., Chen, Y., Adnan, M., Syed Amir Ashraf, Roszko, M., Marcin Bryła, Marek Kieliszek, & Sreenivasan Sasidharan. (2024). Exploring the ancient roots and modern global brews of tea and herbal beverages: A comprehensive review of origins, types, health benefits, market dynamics, and future trends. Food Science & Nutrition, 12(10). https://doi.org/10.1002/fsn3.4346
Kasper, S., Anghelescu, I.-G., Szegedi, A., Dienel, A., & Kieser, M. (2006). Superior efficacy of St John’s wort extract WS®5570 compared to placebo in patients with major depression: A randomized, double-blind, placebo-controlled, multi-center trial [ISRCTN77277298]. BMC Medicine, 4:14. https://doi.org/10.1186/1741-7015-4-14
Klemow, K. M. (2011). Medical attributes of St. John’s wort (hypericum perforatum). Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition. https://www.ncbi.nlm.nih.gov/books/NBK92750/
Li, M.-J., Yin, Y.-C., Wang, J., & Jiang, Y.-F. (2014). Green tea compounds in breast cancer prevention and treatment. World Journal of Clinical Oncology, 5(3), 520–528. https://doi.org/10.5306/wjco.v5.i3.520
Mao, Q. Q., Xu, X. Y., Cao, S. Y., Gan, R. Y., Corke, H., Beta, T., & Li, H. B. (2019). Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe). Foods, 8(6), 185. https://doi.org/10.3390/foods8060185
Mayo Clinic. (2025). St. John’s wort. Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/drugs-supplements-st-johns-wort/art-20362212
Onyemaechi, C. (2024). What is depression? American Psychiatric Association. https://www.psychiatry.org/patients-families/depression/what-is-depression
Peterson, B., & Nguyen, H. (2023). St. John’s Wort. StatPearls. Retrieved December 1, 2025, from https://www.ncbi.nlm.nih.gov/books/NBK557465/
Radeva-Ilieva, M., Stanila Stoeva, Nadezhda Hvarchanova, & Georgiev, K. D. (2025). Green Tea: Current Knowledge and Issues. Foods, 14(5), 745–745. https://doi.org/10.3390/foods14050745
Ramdin, S. (2023, December 9). GINGER – A HISTORICAL JOURNEY THROUGH THE CENTURIES. Medium. https://sramdin20.medium.com/ginger-b38cdc18cf71
Touwaide, A., & Appetiti, E. (2023). Herbs in History: St. John’s Wort. American Herbal Products Association. https://www.ahpa.org/herbs_in_history_stjohnswort
Veronicatxoxo. (2019). Ginger, Local food, Market image. [Photograph]. Pixabay. https://pixabay.com/photos/ginger-local-food-market-food-4546049/
