Essential oils have been rising in popularity recently, thanks in part to the greater and greater number of heath benefits being discovered that essential oils have to offer. While there are hundreds of oils available, there are a few that should be a basic staple in almost every medicine cabinet. Keep in mind, however, that not all products labelled as an essential oil are the same. Some oils are actually synthetic and simply smell nice. For oils to truly affect mood and overall health, they need to be gathered and prepared properly. For the best results, you should only purchase high-quality oils sourced from the purest resources.

Here are 4 of the most essential essential oils.

1. Tea tree oil

Tea tree oil is derived from the Australian Melaleuca tree and is sometimes referred to as Melaleuca oil. Tree tree oil has a wide variety of anti-bacterial properties and is used for a wide range of treatments ranging from killing fungal infections such as athlete’s foot to treating acne. Tea tree oil can also be mixed with witch hazel and used as a toner or astringent. Tea tree oil is not often used for aromatherapy as it doesn’t have the most pleasing scent, but it is also not a totally unpleasant scent either.

2. Eucalyptus oil

Eucalyptus oil is regularly used for respiratory issues ranging from asthma to allergies. Eucalyptus has a strong, pleasant scent and is often used in aromatherapy during the winter months. It is particularly useful for clearing up respiratory issues when combined with steam and eucalyptus branches have been a basic staple in steam rooms and saunas for centuries.

3. Frankincense oil

Frankincense is one of the most expensive oils when processed properly, but also has possibly the widest range of uses. Essential oil uses range from helping with various feminine issues to oral health and even anti-aging. While using it in oil form may be a relatively modern invention, this spice has been used in health care and ancient remedies for centuries. Anyone familiar with the Biblical story of the birth of Jesus may remember that traditionally, the story is told of the three wise men bearing the gifts of gold, frankincense and myrrh to the baby Jesus. Not only is it one of the most expensive oils available today, but it has historically been considered of great value as well.

4. Lavender oil

Lavender oil is probably one of the most versatile oils and is a basic staple in aromatherapy. It is known to be one of the most calming scents and is used in everything from fabric softener to bath salts to massage oils. Dropping a few drops of oil on your pillow each night can have a significant impact on the quality of your sleep and it can even be used to treat burns.