Why does some incense give you a headache?

Burning incense releases gases and particles, among them carbon monoxide and volatile organic compounds (VOCs), and both the American College of Allergy, Asthma and Immunology (ACAAI) and the American Lung Association list headaches among the effects of that smoke. How much you breathe depends on what the stick is made of, how long it burns and how much air the room gets.

Looshi makes artisanal incense, hand-rolled in Karnataka, that smells like a place or a moment you already know. Every stick that burns makes smoke, ours included, so everything below holds for our sticks too.

What's in incense smoke

Incense smoke carries carbon monoxide, nitrogen oxides, formaldehyde and VOCs, according to the American Lung Association, the ACAAI and two medical reviews.

The American Lung Association says studies have found carbon monoxide, nitrogen oxide, sulfur dioxide, formaldehyde and polycyclic aromatic hydrocarbons in it. An ACAAI paper adds carbon and sulfur.

A 2008 review by Lin and colleagues in Clinical and Molecular Allergy adds VOCs such as benzene, toluene and xylenes. Oshan Shrestha's 2020 review in the Journal of the Nepal Medical Association explains that carbon monoxide comes from the incomplete combustion of organic compounds.

Why those gases make your head hurt

Two of the gases in incense smoke, carbon monoxide and VOCs, cause headaches: Shrestha's review lists headaches among the effects of low doses of carbon monoxide and among the short-term symptoms of VOC exposure.

The same review sets eye, nose and throat irritation beside the headache for VOCs. The American Lung Association says all the chemicals in incense smoke can cause health issues including headaches, skin allergies and a range of lung problems.

So a headache after incense comes from the smoke, and what you control is the stick and the room.

Why some sticks and not others

Sticks aren't all made the same way, and fragrance is the largest part of a typical one: Lin and colleagues put it at 35 percent by weight, beside 11 percent adhesive powder.

Dr. Brian Christman, quoted by the American Lung Association, describes most sticks as fragrance, wood chips, coal or potassium nitrate, and an adhesive to hold it together. The ALA advises choosing high-quality, plant-based incense over synthetic varieties.

Looshi sticks are hand-rolled, not dipped, and made with wild honey, natural resins, and activated coconut charcoal, with no synthetic fragrance; you'll find them in our natural incense sticks. If one headache has made you wary of a full box, the Looshi Discovery Set lets you choose four of eight scents, two sticks of each, so you can light every one twice.

How to burn it with less smoke in the room

Less smoke in the room comes from shorter burns, fewer of them and more fresh air: Dr. Christman says the key is to reduce the duration and frequency of exposure and improve ventilation.

He adds that opening a window and burning the incense near it will reduce exposure for everyone in the home. The ACAAI paper names improved ventilation and limiting burn time too.

In practice, light one stick at a time, set it near an open window and leave a gap between burns. For a small space, see our article on burning incense in an apartment, and the journal's note on how many incense sticks to burn a day.

To see what goes into a Looshi stick before you light one again, start with our incense.

Frequently asked questions

Is it normal for incense to give you a headache?

Headaches are a known effect of incense smoke. The American Lung Association says the chemicals in incense smoke can cause headaches, and an ACAAI paper on incense burning lists them among its health risks. Long burns in a room with little fresh air mean more of that smoke in every breath.

Is it harmful to breathe incense smoke?

Breathing incense smoke carries real health risks. A paper presented to the American College of Allergy, Asthma and Immunology lists headaches, breathing problems, skin sensitivity and allergic reactions among them, and the American Lung Association adds a range of lung health problems.

Why do I feel sick after burning incense?

Feeling sick fits what incense smoke carries. Oshan Shrestha's 2020 review in the Journal of the Nepal Medical Association lists dizziness, weakness and nausea among the effects of low doses of carbon monoxide, and nausea and dizziness among the short-term symptoms of VOC exposure. Both gases come off a burning stick.

Can you burn incense safely indoors?

You can lower the risk, but not to zero: the American Lung Association says no indoor burning is completely safe, because it adds pollution to the air. The ALA's advice is shorter, less frequent burns near an open window, and an ACAAI paper adds electric or aromatic vapors as an alternative to burning.