Garlic Supplements

Eating lots of garlic isn't always practical or socially desirable. There are even some people who don't like the taste!

The main reason for not eating lots of garlic is usually the fear of garlic breath. Unfortunately there are - as far as I know - no odourless varieties of garlic available. For this reason many people prefer to buy odorless garlic supplements. These are widely available and come in various forms, the most usual being pills and capsules.

Do Garlic Supplements Work?

So do they work? Do garlic supplements provide the health benefits of garlic? Is taking a dietary capsule good for your health or just a waste of money?

As is so often the case, the answer is "it depends". Garlic supplements vary greatly.


As with all medicines, consult your doctor before taking garlic supplements. In particular garlic should be avoided by those about to undergo surgery as it can disrupt anti-coagulants. Also, research published in 2001 concluded that garlic supplements "can cause a potentially harmful side effect when combined with a type of medication used to treat HIV/AIDS".


The most potent medicinal compound derived from garlic is allicin and it is for this that most people turn to garlic supplements. The chemistry of allicin is complex - it is not present in natural garlic but is released when garlic is crushed. In addition, allicin is unstable and breaks down quickly. Producing garlic supplements that will release significant quantities of allicin is not easy. This might explain their price.

There's no clear consensus on which products are best. One rule of thumb when buying garlic supplements is to check the label for the amount of allicin released. Use this information to compare different brands. Other figures such as "equivalent to x cloves" are not so important. The amount of allicin - if any - depends on the production method. Some people are sceptical that odorless capsules can contain any allicin - after all, it is the sulphorous compunds such as allicin that give garlic its smell in the first place.

Be aware that some garlic supplements list the amount of alliin they contain. That one letter difference is important - it isn't a spelling mistake! Alliin is a precursor compound to allicin however conversion rate between alliin and allicin is extremely variable. On its own an alliin figure is of little value.

Aged Garlic Extract

Even without allicin, capsules might still be of value to some people because of the other sulphides they contain. In particular there has been a lot of research into the possible beneficial effects of aged garlic extract (AGE).

AGE might also be a better choice for people taking blood thinning medication such as warfarin - see this paper.

Garlic Supplements - Summary

If you want to take nutritional garlic supplements, then to get the best medicinal benefits you should go for quality and always check the allicin level on the packet. Even without allicin content, garlic capsules might be of value to some people. Always check with your doctor, especially if you are taking other medication or are due to undergo surgery.