Rooibos vs Green Tea
How rooibos (Aspalathus linearis), a caffeine-free herbal tea, differs from green tea (Camellia sinensis) in caffeine, research and documented cautions, without naming a winner.
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Short answer: rooibos is a herbal tea from Aspalathus linearis and is described as naturally caffeine-free. Green tea is a true tea from Camellia sinensis and is a source of caffeine. The research on each is limited and mostly separate, and the sources we read do not support calling either one better.
What each one is
| Rooibos | Green tea | |
|---|---|---|
| Plant | Aspalathus linearis [1] | Camellia sinensis [2] |
| Plant part used | Not stated in the sources we read | Leaves [2] |
| Type | Herbal tea (tisane), made from a plant other than Camellia sinensis [3] | True tea [2] |
| Processing | Studies used fermented or unfermented rooibos [1] | Leaves steamed, pan fried and dried but not fermented [2] |
| Caffeine | Described as naturally caffeine-free [4] | A source of caffeine; a US FDA table gives a typical 37 mg per 12-fluid-ounce serving [2][5] |
| Tannin | Described in one review as low in tannin [3] | Not compared in the sources we read |
| Traditional association | Half of the human studies in a scoping review were done in South Africa [1] | NCCIH says the tea plant was first cultivated in China and that evidence of tea used for health purposes goes back about 3,000 years [2] |
Plant names on this page were checked against GBIF, which lists Aspalathus linearis and Camellia sinensis as accepted names. [6]
What research shows, one tea at a time
| Question | What the source found | Strength of evidence | Form studied |
|---|---|---|---|
| Rooibos and health markers in people | A 2023 scoping review of 18 publications with 488 participants (ages 6 to 83) reported better lipid profiles, antioxidant status and blood glucose, but said the findings rest on a limited number of studies and a small total sample. [1] | Promising but limited | Rooibos tea, 200 to 1,200 ml in studies |
| Rooibos and skin or other beverage outcomes | A 2026 narrative review of beverages and skin health called the evidence for rooibos limited or indirect. [7] | Insufficient evidence | Mixed beverages |
| Green tea overall | NCCIH says definite conclusions cannot yet be reached on whether green tea helps for most uses people try it for. [2] | Insufficient evidence | Drink and extract |
| Green tea and cholesterol | Green tea reduced total and LDL cholesterol to a small extent, but most of those trials evaluated extract supplements and not the drink. [2] | Mixed | Mostly extract |
A scoping review maps what exists and does not rate study quality, so it describes what small studies reported and is not proof of benefit.
Evidence head to head
We found one trial that gave the two teas to the same people. Seventeen healthy volunteers each received a single 400 ml serving of green tea, black tea or rooibos in random order (a crossover design). Rooibos significantly lowered the activity of angiotensin-converting enzyme (ACE, a blood-pressure-related enzyme) at 30 and 60 minutes, and green tea did so in people with certain ACE gene types. Nitric oxide levels did not change significantly. [8] This is a laboratory marker after a single serving. It says nothing about blood pressure or heart disease over time, and no trial we found compared the two teas on a clinical outcome. Proper evidence not found for a head-to-head clinical comparison. We searched PubMed for rooibos and green tea together in randomized, crossover or trial studies (2 records, this one trial and a general review). [9]
No universal winner
If you want to avoid caffeine, rooibos is described as caffeine-free and green tea is not. If a medicine or condition makes you cautious, the documented cautions above differ, and a pharmacist can check them against your list. Beyond that, the sources we read do not rank them. Related reading: rooibos tea, green tea as a drink and herbal tea vs true tea.
Frequently asked questions
Does rooibos have caffeine?
A 2026 study of rooibos describes it as a naturally caffeine-free herbal tea. Blends and flavored products can contain other ingredients, so check the label. [4]
Does green tea have more caffeine than rooibos?
Green tea is a source of caffeine (a US FDA table lists a typical 37 mg in 12 fluid ounces), and rooibos is described as caffeine-free. [2][5][4]
Is rooibos or green tea better for blood pressure?
Proper evidence not found for a clinical comparison. One crossover trial in 17 healthy people measured an enzyme marker after a single serving and did not measure blood pressure. [8]
Can either tea harm the liver?
Rarely. Liver injury has been reported mainly with green tea extracts in tablets or capsules, and there is a case report linked to rooibos. If you have liver disease or take medicines cleared by the liver, ask a clinician. [2][10]
Are there contaminants in rooibos?
A European study found pyrrolizidine alkaloids in 98% of 203 samples (all 2024 samples were below the EU limit) and Alternaria mold toxins in every sample. It estimated limited risk at average levels. [4]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety
Rooibos.
- Liver: one published case report attributes liver injury to rooibos, and its authors say liver toxicity, though rare, is probably underdiagnosed. A single case report cannot show how often this happens. [10]
- Contaminants: a 2026 study of 203 rooibos samples from 18 European countries found pyrrolizidine alkaloids (plant toxins) in 98% of them, with a mean of 47 μg/kg. All samples from 2024 were below the EU maximum level of 400 μg/kg, although the authors note sporadic exceedances over the 2020 to 2026 comparison. Mold toxins from Alternaria were found in all samples. The toxins moved into the brewed infusion in transfer experiments. The authors estimated a limited risk at average contamination levels. [4] See pyrrolizidine alkaloid teas.
- Medicines and pregnancy: Proper evidence not found in the sources we read. We did not find an NCCIH, MedlinePlus or EMA herbal page for rooibos (the addresses we tried returned "not found"), so we make no claim either way. Ask a pharmacist if you take medicines or are pregnant.
Green tea.
- NCCIH reports no safety concerns for green tea as a drink in adults, other than caffeine. Side effects of extract supplements include nausea, constipation, abdominal discomfort and higher blood pressure. Liver injury is uncommon and mostly linked to extracts in tablet or capsule form, and people with a particular immune gene variant appear more susceptible. [2]
- Medicines: green tea at high doses reduced blood levels of the beta-blocker nadolol, green tea extract reduced blood levels of the statin atorvastatin, and an NCCIH-funded study found an interaction with raloxifene. [2] See how interactions work.
- Pregnancy and breastfeeding: because green tea contains caffeine, NCCIH advises asking a health care provider about caffeine intake, and notes caffeine can pass into breast milk. [2]
If you notice warning signs of liver trouble with any product, see liver safety.
References
- Afrifa D, et al. The health benefits of rooibos tea in humans (Aspalathus linearis): a scoping review. Journal of Public Health in Africa, 2023 (PubMed abstract). Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Green Tea: Usefulness and Safety. Read 2026-10-23.
- Review of tea and herbal beverages, PubMed Central (PMC11521711). 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. Read 2026-10-23.
- Occurrence of tropane alkaloids, pyrrolizidine alkaloids and mycotoxins in rooibos: a comprehensive safety assessment. Food Additives & Contaminants Part A, 2026 (PubMed abstract). Read 2026-10-23.
- US Food and Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much?. Read 2026-10-23.
- GBIF Secretariat. GBIF Backbone Taxonomy species match service. Names checked 2026-10-23: Camellia sinensis, Aspalathus linearis, Matricaria chamomilla (accepted; Matricaria recutita is a synonym), Melissa officinalis, Valeriana officinalis.
- Dietary beverages and cutaneous health: mechanisms, clinical evidence, and practical implications for dermatologists. Clinics in Dermatology, 2026 (narrative review, PubMed abstract). Read 2026-10-23.
- Effects of green tea, black tea and Rooibos tea on angiotensin-converting enzyme and nitric oxide in healthy volunteers. Public Health Nutrition, 2010 (PubMed abstract). Read 2026-10-23.
- US National Library of Medicine. PubMed search of title and abstract records run through the NCBI E-utilities on 2026-10-23; search terms and record counts are listed in the evidence log for this group.
- Carrier P, et al. Rooibos, a fake friend. Clinics and Research in Hepatology and Gastroenterology, 2021 (case report, PubMed abstract). Read 2026-10-23.