Kyolic Aged Garlic Extract

Aged garlic extract is well tolerated and simple to take. These are the questions our naturopaths ask in store, and they're mostly about your medicines and what you're hoping it'll do.

A good fit if

• You want support through winter and you'll take it for the whole season
• Raw garlic or garlic capsules have put you off before
• You're happy with an honest, modest effect rather than a promise

Check with us first if

• You take warfarin or any other blood thinner. Garlic may add to the effect, and the evidence on warfarin is mixed.
• You take antiplatelet medicine or have a bleeding disorder.
• You have surgery coming up. The published advice is to stop high doses 7 to 10 days beforehand.
• You take diabetes medicine, because low blood sugar has been reported with garlic taken alongside chlorpropamide.
• You take HIV medicine. Garlic reduces how well saquinavir works.
• You're pregnant or breastfeeding. There's no safety evidence either way.
• It's for a child. There's no trial data in children, and permitted cold wording comes with an adults-only or under-2 label statement.

• Aged garlic extract. Best known for: The trial on immunity and how severe colds get. Absorption: Ageing turns the harsh sulfur compounds into water-soluble S-allyl-cysteine. Typical use: Winter support, taken through the season. It isn't a Schedule 1 name.
• Garlic powder tablets. Best known for: Most of the heart and cholesterol trials. Absorption: Dried bulb, usually standardised to how much allicin it can produce. Typical use: Heart and cholesterol support. Schedule 1 items 2306, 2308 and 2309.
• Aged black garlic. Best known for: A milder taste, with the same S-allyl-cysteine marker. Absorption: Aged with heat and humidity rather than by soaking. Typical use: Only one small trial, in people already on medication.
• Garlic oil. Best known for: A chemically different product, made by steam distillation. Absorption: Contains allyl sulfides rather than allicin. Typical use: The form with a documented interaction with the CYP2E1 liver enzyme. Schedule 1 item 2310.

Reference values. There's no recommended intake for aged garlic extract. Garlic is a food and a herb, not a nutrient, so the NHMRC doesn't set one.

Typical supplemental range. The cold-season trial used 2.56 g a day of aged garlic extract in capsules, taken for 90 days. A trial of aged black garlic measured its dose by its S-allyl-cysteine content instead, at 0.25 mg a day for 12 weeks.

Upper level. None of the garlic entries on Australia's permitted ingredients list (Schedule 1) set a maximum daily dose, and there's no NHMRC upper limit.

Worth knowing. We don't know what Australian aged garlic labels actually contain, so we won't tell you a product matches the trial dose. You may see a figure of over 1,200 mg a day quoted widely, but it comes from a paper that has since been retracted, so we don't use it. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Fresh garlic clove: about 2.7 g a clove. It's the raw material, but eating it doesn't give you the aged compounds

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• You take a blood thinner such as warfarin. Garlic may strengthen its effect. One review of trial data found aged garlic didn't significantly change warfarin's effect but rated that evidence low quality, and another found garlic lowered warfarin levels. Check with the doctor who prescribes it.
• You take antiplatelet medicines or have a bleeding disorder. Garlic can change how platelets and blood clotting work.
• You have surgery coming up. Published clinical advice is to stop high doses 7 to 10 days beforehand, because garlic can lengthen bleeding time.
• You take HIV medicines. Garlic makes saquinavir less effective.
• You take medicines that lower blood glucose. Low blood sugar has been reported with garlic and chlorpropamide.
• You're allergic to garlic. Contact dermatitis, hives, angioedema, anaphylaxis and light-triggered allergy have been recorded, though rarely.
• You're pregnant or breastfeeding, or it's for a child. We found no safety data either way.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.