{"ok":true,"entry":{"slug":"olive-leaf","kind":"supplement","name":"olive leaf","aliases":["oleuropein","Olea europaea"],"brands_sg":["California Gold Nutrition","NOW Foods","Swanson Vitamins","Nutricost","Nature's Answer"],"class":"botanical","tags":["immune","heart"],"use_for":"meta-analysis: small falls in systolic bp and triglycerides","use_after":null,"use_duration":null,"take_with":null,"pros":["12 rcts, 819 adults pooled in a 2022 meta-analysis","systolic bp fell 3.86 mmhg; triglycerides 9.51 mg/dl","2024 review: 12 more rcts, 683 adults, mixed results"],"cons":["no change in glucose, liver, kidney or inflammation","evidence for those outcomes graded low-to-very low","doses ranged from 5 mg to a 990 ml daily infusion"],"dose_note":"the two reviews here pool products rather than converge on an amount: the 2022 meta-analysis of 12 controlled trials in 819 participants reports pooled changes — triglycerides down 9.51 mg/dl and systolic blood pressure down 3.86 mmhg — without a single studied dose, and notes the largest subgroup effects were in people with hypertension rather than in general adults; the 2024 systematic review of 12 human randomised controlled trials in 683 participants states outright that the studies described different dosages and forms of supplementation, ranging from 5 mg a day of hydroxytyrosol to 990 ml a day of olive leaf infusion, and that further research is needed to determine optimal dosing and duration; hsa's october 2025 annex a (118 rows) and annex b (4 rows) do not list olea europaea or oleuropein, and hsa's tables 4 and 5 cap vitamins and minerals only, so no singapore daily limit exists for it","dosage":{"ul":null,"unit":null,"fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["on blood-pressure medicine — systolic blood pressure fell across the pooled trials","the larger subgroup effects were in people with hypertension, not in general adults","not listed in hsa's prohibited or restricted annexes — that is not a safety finding","no singapore daily limit — hsa tables 4–5 cover vitamins and minerals only"],"clashes":[],"sources":[{"id":"epmc_ole_2022","url":"https://europepmc.org/article/MED/36271405","label":"Razmpoosh et al., The effects of olive leaf extract on cardiovascular risk factors in the general adult population: a systematic review and meta-analysis of RCTs (Diabetol Metab Syndr 2022, PMID 36271405) — pooled results","quote":"Twelve studies (n = 819 participants) … OLE supplementation significantly decreased triglyceride (TG) levels (WMD = - 9.51 mg/dl) … and systolic blood pressure (SBP) (WMD = - 3.86 mmHg)","accessed":"2026-08-27"},{"id":"epmc_ole_2022_limits","url":"https://europepmc.org/article/MED/36271405","label":"Razmpoosh et al. 2022 (PMID 36271405) — null outcomes, subgroups and evidence quality","quote":"no meaningful changes were seen in glucose hemostasis, liver and kidney, or inflammatory markers … the quality of evidence for glucose hemostasis variables, liver, kidney, and inflammatory markers, were low-to-very low","accessed":"2026-08-27"},{"id":"epmc_oleuropein_2024","url":"https://europepmc.org/article/MED/39334699","label":"Frumuzachi et al., Systemic Health Effects of Oleuropein and Hydroxytyrosol Supplementation: A Systematic Review of RCTs (Antioxidants 2024, PMID 39334699) — scope and dose range","quote":"systematic review analyzed 12 human randomized controlled trials (RCTs), involving 683 participants … The studies described different dosages and forms of supplementation, ranging from 5 mg/d HT to 990 mL/d olive leaf infusion","accessed":"2026-08-27"},{"id":"epmc_oleuropein_2024_limits","url":"https://europepmc.org/article/MED/39334699","label":"Frumuzachi et al. 2024 (PMID 39334699) — authors' conclusion","quote":"Despite the mixed outcomes, OLE and HT supplementation show potential for improving some of the cardiometabolic health outcomes and bone, joint, and cognitive health. However, further studies are necessary to understand their benefits better and address existing limitations.","accessed":"2026-08-27"},{"id":"hsa_prohibited","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev. No. 001 (October 2025), Annex A (118 rows) and Annex B (4 rows) — Olea europaea / olive leaf / oleuropein NOT LISTED in either (Annex A neighbours: 58. Juniperus sabina, 73. Nerium indicum (oleander))","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list.","accessed":"2026-08-27"},{"id":"hsa_hs_guidelines","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026), clause 4.8 with Tables 4–5 (vitamins and minerals only — no botanical or bee-product rows)","quote":"4.8 HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5.","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/olive-leaf","label":"iHerb Singapore — Olive Leaf category page, default listing order","quote":"1 - 48 of 57 results … California Gold Nutrition, EuroHerbs™ Olive Leaf Extract … NOW Foods, Olive Leaf Extract, 500 mg … Swanson Vitamins, Extra Virgin Olive Oil … Nutricost, Olive Leaf Extract, 750 mg … Nature's Answer, Olive Leaf Extract Standardized","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:27.496708+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}