Eucalyptus tea: is it safe to drink?

Eucalyptus is technically poisonous, but it depends on amount.

Concentrated Eucalyptus Oil, like an essential oil, should always be kept out of reach of children and have a childproof cap, for example (http://www.poisons.co.nz/fact.php?f=27). It is a dangerous and confusing point because, like clove oil which is also poisonous in sufficient amounts, it is used in various remedies in small amounts. Of course, when you have a concentrated oil, "sufficient amounts" is relatively small. Putting a leaf in some tea is quite different.

There are a number of places on the web selling Eucalyptus tea and giving recipes, but the general recommendation is not to drink too much or make it too strong. The general recommended amount is 1/2 tsp dried leaves or one torn up fresh leaf per cup of water, and 1-3 cups per day.

This responsible looking website notes some safety issues: http://www.eucalyptusoil.com/safety

This website gives more details of the chemicals found in Eucalyptus, and tells you how to make a tea. It also gives a list of medical conditions which indicate you shouldn't drink Eucalyptus tea. http://www.livestrong.com/article/523149-what-is-eucalyptus-tea-good-for/

Another website also contraindicates eucalyptus for use with some drugs - 5-Fluorouracil, Pentobarbital, Amphetamine (I can't provide source because not enough reputation to post the extra link)

Note: Many things that are contained in various herbal remedies and so on contain active ingredients that can ... have all sorts of effects. So everyone should research them themselves or check with a Natural Health Practitioner or doctor first before taking them with medications, or giving them to small children, pregnant women, asthmatics or any high-risk health group.

Eucalyptus tea is a common remedy for sinuses. Unlike most medicinal plants that people have heard of, eucalyptus is dangerous in larger amounts. As a tisane (tea), you should have a max of 2 leaves per cup (8 oz.) and three cups per day. Having somewhat more then this will not actually harm you, but may cause particularly unpleasant nausea for two days and basically make you miserable. To cause actual damage to the body, you would need much more then that or need to be using the EO. Eucalyptus should not be used to infused olive oil. Although there is no information on this online seemingly, I have personally done this and that is how I came to know information about eucalyptus. Tisanes from most herbs also do not impart much flavor, and usually need regular green or white tea added to the tisane for a good taste. There are some exceptions and I have not had eucalyptus as a tea myself. Eucalyptus oil should not be used by epileptics. I see nothing that says there is any danger for using the tea if you are prone to seizures, however, I would wait until the the leaves dry out some or else have the non-seizure guy make the tea for the seizure guy if he is trying some.