Roots of Renewal: The Healing Power of Medicinal Herbs
From a 5,000 year old clay tablet to a Nobel Prize. Discover what the plants in your kitchen and garden can really do, what science has proven, and how to use them wisely at every age.
- Plants are the source of real medicines: aspirin, artemisinin, metformin and vincristine all trace back to herbs.
- Some herbs have good trial evidence for specific problems, such as ginger for nausea or curcumin for knee arthritis.
- “Natural” does not mean “safe”. Herbs can clash with medicines, so tell your pharmacist.
- Food-level use (cooking, gentle teas) is the easiest and gentlest way to begin.
- Never stop a prescribed medicine because of a herb. Use herbs as support, not substitutes.
- Pregnant, breastfeeding, a child, older, or on medicines? Ask a professional first.
Fresh from the garden
Images generated with Canva for illustration. Real plants vary in colour and size.
What exactly is a medicinal herb?
A medicinal herb is a plant, or a part of a plant such as the leaf, root, seed, flower or bark, that people use to prevent, ease or treat illness and to support well-being.
The word herb in everyday life often means a leafy cooking plant like basil or mint. In medicine it has a wider meaning: any plant material valued for its healing properties. A plant makes hundreds of natural chemicals called phytochemicals. A few of them act on the human body, and those are the ones scientists study.
People have trusted plants for a very long time. Researchers estimate that our ancestors used plants as medicine at least 60,000 years ago25, and around 26,000 plant species have a documented medical use24. Today the practice is still alive in kitchens, village gardens, Ayurveda, Traditional Chinese Medicine, and modern pharmacies.
Herbs are not all equal. Some are backed by solid clinical trials. Others have only tradition behind them. This guide helps you tell the difference.
Traditional medicine comprises knowledge, skills and practices that pre-date modern biomedicine, grown from experience in different cultures, and emphasises nature-based remedies and holistic care. WHO describes it as an important resource for health systems worldwide.
Paraphrased from the WHO Global Report on Traditional and Complementary Medicine 2019 1Six herbs, six stories, what science says
Pick a health goal to light up the herbs that have been studied for it. Every card shows the plant, the traditional use, and the evidence in plain language.
Turmeric
Ancient use: A golden spice in Ayurvedic and Chinese medicine for wounds, digestion and joint stiffness.
Science: The active compound curcumin has been tested in knee osteoarthritis. An umbrella review of 11 meta-analyses found lower pain scores and better joint function and stiffness4. Trials showing benefit mostly used about 1,000 mg a day of curcumin5, far more than a spoonful of curry powder gives.
Ginger
Ancient use: Chewed, brewed or cooked to settle the stomach and warm the body.
Science: A 2022 meta-analysis of 13 trials (1,174 women) found ginger eased the overall symptoms and severity of nausea in pregnancy compared with placebo, though it did not clearly reduce vomiting7. An earlier review of 12 trials saw no increase in side effects like heartburn or drowsiness8.
Tulsi (Holy Basil)
Ancient use: Called the “queen of herbs” in Ayurveda, grown in courtyards, used for colds, stress and long life29.
Science: A systematic review gathered 24 human studies (1,111 people) on tulsi. Most outcomes were about blood glucose, cholesterol, blood pressure, immunity and mood, and results were generally positive. But only three trials had 100 or more participants, so the evidence is early9.
Ashwagandha
Ancient use: A root tonic in Indian medicine, taken for energy, sleep and resilience.
Science: A 2025 meta-analysis of 15 trials (873 adults) found ashwagandha reduced perceived stress, anxiety scores and cortisol at 8 weeks compared with placebo, but did not improve quality of life10. A 2024 review of 9 trials (558 people) agreed, and noted that four trials reported mild to moderate side effects11.
Peppermint
Ancient use: Peppermint tea after meals, a worldwide habit for gas, bloating and an upset stomach.
Science: A 2019 meta-analysis of 12 trials (835 people) found enteric-coated peppermint oil beat placebo for global IBS symptoms and abdominal pain12. A 2022 update still found a benefit, but rated the certainty of evidence very low and noted more side effects13. Heartburn is the most common complaint14.
Aloe Vera
Ancient use: Leaf gel placed on burns, sun damage and wounds in many cultures.
Science: One review found burns treated with aloe vera healed on average 8.79 days faster than controls15. A 2024 meta-analysis of 9 trials in second degree burns found about 3.76 days faster healing than other topical agents, with no extra infections, but rated the evidence low to very low quality16. A Cochrane review found too little high quality evidence for wounds in general17.
How to read the evidence dots: They are an editorial summary of the reviews cited on each card, written to help readers compare at a glance. They are not a formal medical grading, and evidence can change as new trials are published.
Herbs through the stages of life
Needs and risks change as we grow. Tap a stage for sensible, general guidance.
Children: food first, always
- Herbs as ordinary foods and cooking spices are the gentlest way to include them.
- Concentrated extracts, capsules and essential oils are not well studied in children. Ask a pediatrician before using them.
- Children can react more strongly than adults. Never copy an adult dose.
- Keep herbal products and oils out of reach, like any medicine.
Teens: build habits, skip the hype
- Exam stress and sleep problems respond best to sleep, movement, food and talking to someone you trust.
- Most “stress” and “energy” supplements have been tested in adults, not teenagers.
- Warm ginger or mint tea is a fine ritual. Strong supplements and “detox” products are not needed.
- Feeling low or anxious for weeks? That deserves real support from a doctor or counsellor.
Adults: the most studied group
- Most clinical trials for turmeric, ashwagandha, tulsi and peppermint oil were done in adults, often for 4 to 12 weeks10.
- Choose one herb at a time, start low, and note how you feel. A simple log helps (download one below).
- Tell your pharmacist about every herb, tea and supplement you take, as well as your prescriptions.
- Think about timing: many herbal effects take weeks, not hours.
Pregnancy and breastfeeding: ask first
- Ginger is the best studied herb for pregnancy nausea. Reviews found it helped nausea and did not raise the rate of side effects, with studied doses around 1 gram a day for limited periods7,8.
- For most other herbs, pregnancy safety data is thin. Do not assume “natural” is safe for the baby.
- Concentrated extracts such as ashwagandha supplements need a clinician’s approval before use.
- Bring every product to your midwife or doctor, including teas.
Older adults: benefits and interactions
- Joint stiffness is a common reason for trying curcumin. Evidence for knee osteoarthritis is encouraging4.
- Many older adults take several medicines, which raises the chance of herb-drug interactions27.
- Garlic, ginseng, ginger and feverfew can add to bleeding risk with blood thinners26.
- Use a weekly pill organiser and keep a written list of everything you take.
The numbers behind the leaves
Real data from the World Health Organization, peer reviewed journals and the Nobel Foundation. Tap the small numbers to jump to the source.
Herbal medicine is growing inside health systems
Number of WHO Member States reporting each item. Survey results published in 2019, compared with 2012.
Bar length is scaled to a maximum of 194 Member States. Source: APHA Public Health Newswire summary of the WHO 2019 report 2.
What the clinical trials found
- Turmeric and curcumin: An umbrella meta-analysis of 11 meta-analyses of randomised trials found curcumin lowered pain (VAS) and improved WOMAC pain, stiffness and function scores in osteoarthritis, and shortened medication use4. An earlier review of 8 trials supported about 1,000 mg a day of curcumin5. A pooled analysis of 25 trials (2,253 people) found benefits for both osteoarthritis and rheumatoid arthritis6.
- Ginger for nausea in pregnancy: 13 trials with 1,174 women found ginger significantly relieved general symptoms (odds ratio 7.475) and nausea severity versus placebo, but not vomiting7. Up to 85% of pregnant women experience nausea and vomiting7.
- Ashwagandha: In 15 trials with 873 adults, perceived stress fell by 4.88 points on the Perceived Stress Scale versus placebo at 8 weeks, and cortisol dropped significantly, but quality of life did not improve10.
- Tulsi: 24 human studies with 1,111 participants were reviewed. Only three trials had 100 or more people, and durations ran from 2 to 13 weeks9.
- Peppermint oil for IBS: 12 trials with 835 patients. The risk ratio for improved global symptoms was 2.39 versus placebo, and you would need to treat about 3 people for one extra person to benefit12.
- Aloe vera for burns: Healing was about 3.76 days faster in 9 trials of second degree burns, but the evidence quality was low to very low16. In a wound-care review, one aloe dressing cost 2.40 Indian rupees versus 4.92 for a silver sulfadiazine dressing18.
- From plant to drug: At least a quarter of prescription drugs in the US come from substances found only in plants, according to SciShow’s review of the literature21. Vincristine, from the rosy periwinkle, helped raise childhood leukaemia success rates from about 10% in the 1960s to over 80% today21.
- Artemisinin: Combination therapy based on this sweet wormwood compound is estimated to cut malaria deaths by more than 20% overall and more than 30% in children30. Tu Youyou received half of the 2015 Nobel Prize in Physiology or Medicine for it20.
- Safety signal: A review of 49 case reports plus two studies with 15 more reactions linked herbal products, including St John’s wort, ginseng and chamomile, to harmful interactions with warfarin, chemotherapy and transplant drugs28.
Peppermint oil: how many people benefit?
“Number needed to treat” is how many people must take a treatment for one extra person to improve.
2019 meta-analysis: about 1 in 3
2022 update: about 1 in 4
The 2019 review reported NNT 3 for global symptoms; the 2022 update reported NNT 4 and rated the certainty very low 12,13.
Turmeric latte reality check
Why a golden latte is not the same as a curcumin trial.
SciShow calculated that matching 8,000 mg from lattes would need roughly 88 to 400 lattes a day. Spice is still a healthy flavour, but it is not a trial dose 23.
Thousands of years, one thread
The story of herbal medicine is a story of careful observation, passed from healer to healer, and then tested in the lab.
Early humans use plants as medicine. Researchers estimate this long history of plant use from archaeological and ethnographic evidence25.
A Sumerian clay slab lists 250 plants for preparing medicines, one of the oldest written medical records21.
Ge Hong’s emergency handbook describes preparing sweet wormwood (qinghao) by wringing out the fresh juice instead of boiling it. This clue would matter 1,600 years later19,22.
Li Shizhen recommends qinghao tea to treat malaria in his famous pharmacopoeia25.
Project 523. Tu Youyou’s team reviewed ancient texts, revisited the old cold-extraction hint, and isolated artemisinin from sweet wormwood22,25.
Nobel Prize. Tu Youyou is honoured for “her discoveries concerning a novel therapy against Malaria”20.
Long term benefits worth caring about
Herbs matter far beyond a cup of tea. Here is what a thoughtful, evidence-aware approach can offer over the years.
Everyday health habits
Cooking with ginger, turmeric and mint turns daily meals into small acts of care. Food-level use is gentle, low cost and sustainable over a lifetime.
Less medicine, where evidence allows
For knee osteoarthritis, the umbrella review found curcumin shortened the time people relied on medication4. That is a reason to ask your clinician, not a reason to stop prescriptions.
Access and affordability
In places with limited resources, a low cost option such as aloe vera for partial thickness burns may help, as one wound-care evidence summary noted18.
Cultural wisdom and biodiversity
Herbal knowledge is living heritage. Protecting plants and the communities who know them protects tomorrow’s medicines, because a plant lost may be a cure lost21.
New drugs from old plants
Drug discovery keeps learning from traditional remedies. Aspirin from willow, artemisinin from wormwood and metformin from goat’s rue are proof21,24.
Empowered patients
When people understand what a herb can and cannot do, they ask better questions and make safer choices with their care team.
An honest note on long term data: Most herbal trials last 2 to 13 weeks9. For ashwagandha, reviewers say more information is needed on long term safety11. That is why this guide says “may help” and not “will cure”. Long term benefits are strongest for food-level, balanced use and weakest for high-dose supplements taken for years without advice.
Six things people get wrong about herbs
Tap a card to flip it and reveal what the evidence really says.
Kamala and the cup of golden tea
A gentle story about a common and sensitive mistake: stopping a prescribed medicine because a herb “worked for a neighbour”.
The ache that would not leave
Kamala, 63, loved her morning walks in the garden. Lately her knees hurt on every step. She also takes tablets for high blood pressure, which she dislikes because she “feels fine without them”.
A neighbour’s advice
“Drink turmeric tea and drop the tablets,” her neighbour said kindly. “My pain vanished in a month.” Kamala wanted to believe it. She loved the idea of being free from medicine.
The quiet mistake
Kamala stopped her blood pressure tablets for three days. She felt no different, so she felt sure she was right. But high blood pressure often has no symptoms. Her headaches and a pounding feeling in her ears were warning signs she nearly ignored.
An honest conversation
Her daughter noticed and took her to the local pharmacy. The pharmacist did not scold. She explained that curcumin shows promise for knee pain, that turmeric in food is a fine addition, and that blood pressure tablets protect the heart and brain even when she feels well. She also checked Kamala’s other medicines for interactions.
Small steps, steady walks
Kamala restarted her tablets. She added turmeric and ginger to her cooking, began gentle physiotherapy exercises, and kept a simple herb and medicine log. Months later she was walking again. She told her neighbour: “Herbs are a friend, not a replacement for my doctor.”
Be the person who asks the question before changing the pill. One conversation can protect a heart.
When to seek medical advice
Use herbs thoughtfully. Know the signs that mean it is time to stop and call a professional.
Stop and get medical help if you notice
- Swelling of the face, lips or throat, hives, or trouble breathing after a herb
- Yellow skin or eyes, dark urine, or severe stomach pain
- Unusual bruising or bleeding, black stools, or a nosebleed that will not stop
- Palpitations, fainting, or very high or very low blood sugar readings
- Symptoms that last more than a couple of weeks, keep returning, or get worse
- Fever with a stiff neck, chest pain, sudden weakness, or confusion
Smart habits before you start
- Ask a doctor or pharmacist first if you are pregnant, breastfeeding, have a chronic illness, or take any medicine
- Start with food and mild teas before supplements
- Try one herb at a time, start low, and write down what you notice
- Buy from reputable brands, and look for independent quality testing on supplements
- Tell your surgeon or dentist about herbs before any procedure26
- Never replace prescribed medicine with a herb, and never give adult products to children
Quick safety self check
Tick anything that applies to you. You will get a general nudge about who to talk to. This is not a diagnosis.
Videos worth your time
Short, science-minded videos on YouTube. Tap a thumbnail to watch. The links open in a new tab.
Downloads and credible references
Take the guidance with you, and read the original sources yourself.
References
- World Health Organization. WHO global report on traditional and complementary medicine 2019. Geneva: WHO; 2019. who.int
- APHA Public Health Newswire. WHO launches report on traditional and complementary medicine at World Health Assembly. 3 Sept 2019. apha.org
- World Health Organization. Traditional, complementary and integrative medicine (topic overview). who.int
- Jamilian P, et al. The efficacy of curcumin in relieving osteoarthritis: a meta-analysis of meta-analyses. Phytother Res. 2024;38(6):2875-2891. PubMed 38576215
- Daily JW, Yang M, Park S. Efficacy of turmeric extracts and curcumin for alleviating the symptoms of joint arthritis: a systematic review and meta-analysis of randomized clinical trials. J Med Food. 2016;19(8):717-729. PubMed 27533649
- Examine.com. Study summary: Turmeric extract and curcumin for arthritis (meta-analysis of 25 RCTs, 2,253 participants). 4 Oct 2022. examine.com Secondary summary of the original meta-analysis.
- Hu Y, et al. Effect of ginger in the treatment of nausea and vomiting compared with vitamin B6 and placebo during pregnancy: a meta-analysis. J Matern Fetal Neonatal Med. 2022;35(1):187-196. PubMed 31937153
- Viljoen E, et al. A systematic review and meta-analysis of the effect and safety of ginger in the treatment of pregnancy-associated nausea and vomiting. Nutr J. 2014;13:20. PubMed 24642205
- Jamshidi N, Cohen MM. The clinical efficacy and safety of tulsi in humans: a systematic review of the literature. Evid Based Complement Alternat Med. 2017;2017:9217567. PMC5376420
- Bachour G, et al. Effects of ashwagandha supplements on cortisol, stress, and anxiety levels in adults: a systematic review and meta-analysis. BJPsych Open. 2025. doi:10.1192/bjo.2025.10136. PMC12242034
- Vijayakumar V, et al. Effects of ashwagandha (Withania somnifera) on stress and anxiety: a systematic review and meta-analysis. Explore (NY). 2024;20(6):103062. PubMed 39348746
- Alammar N, et al. The impact of peppermint oil on the irritable bowel syndrome: a meta-analysis of the pooled clinical data. BMC Complement Altern Med. 2019. PMC6337770
- Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome. Aliment Pharmacol Ther. 2022;56(6):932-941. PubMed 35942669
- Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis. J Clin Gastroenterol. 2014;48(6):505-512. PubMed 24100754
- Maenthaisong R, et al. The efficacy of aloe vera used for burn wound healing: a systematic review. Burns. 2007;33(6):713-718. PubMed 17499928
- Effects of Aloe vera on burn injuries: a systematic review and meta-analysis of randomized controlled trials. J Burn Care Res. 2024;45(6). EBSCO record
- Dat AD, et al. Aloe vera for treating acute and chronic wounds. Cochrane Database Syst Rev. PubMed 22336851
- Wound Healing and Management Collaborative. WHAM evidence summary: Aloe vera for treating burns. WCET Journal. 2022;42(2). Download
- Nobel Prize Outreach. Tu Youyou, Women who changed science. nobelprize.org
- The Nobel Prize in Physiology or Medicine 2015: Tu Youyou, laureate page. nobelprize.org
- SciShow. 4 Medicinal Plants that Are Incredibly Good for You (video and transcript). 2016. YouTube
- SciShow. How an Ancient Remedy Became a Modern Cure for Malaria (video and transcript). 2021. YouTube
- SciShow. The Sad Truth About the Turmeric in Your Golden Latte (video and transcript). 2018. YouTube
- Royal Society of Chemistry, Education in Chemistry. From traditional remedies to modern medicines. edu.rsc.org
- Complementary Medicines Australia. Ancient roots: how traditional remedies became conventional medicines. cmaustralia.org.au
- Mayo Clinic Health Letter via Newswise. Natural herbal supplements aren’t always safe. newswise.com
- NCCIH, National Institutes of Health. Clinical Digest: Herb-drug interactions. Dec 2024. nccih.nih.gov
- British Pharmacological Society. Herbal products may compromise prescription drugs and cause serious side effects (review in Br J Clin Pharmacol). 24 Jan 2018. bps.ac.uk
- News-Medical. Tulsi (holy basil): ancient herb, modern medicine? news-medical.net
- AsianScientist. Chinese TCM expert wins 2015 Nobel Prize in Medicine (citing the Nobel Foundation). 6 Oct 2015. asianscientist.com
Medical disclaimer: This guide is for education and awareness. It is not medical advice and does not replace consultation with a qualified health professional. Herbal products can interact with medicines and may not suit pregnancy, childhood, or certain medical conditions. Never start, change, or stop a prescribed treatment without talking to your doctor or pharmacist. Figures and findings were taken from the sources listed, which may be updated over time. Herb photos are AI-generated images created with Canva, and the drawings are original artwork. The story of Kamala is fictional.