I often hear people recommend clove essential oil for teething babies. Simply put, clove isn't safe for babies under the age of two. Let me tell you why clove oil for teething is bad advice...
Clove essential oil (eugenia caryophyllata) is a spicy, warming oil steam distilled from the buds and stems of clove tree. Clove is often recommended as a pain reliever but the real beauty of clove oil is that it supports oral health. Clove oil is antimicrobial and acts as an antiseptic. This makes it a great oil for cavities, gum disease, and other oral health issues. However, this oil is for adults, not teething babies.
Clove contains high levels of eugenol. Since eugenol is not very common, some people discover allergies to clove. Additionally, clove is a warming oil and in concentrated form it can burn your sensitive mucus membranes. Clove has an affect on other body systems too. It can cause blood sugar to drop and inhibit blood clotting. Pregnant women and those who are nursing should not use clove oil. Furthermore, risks of clove oil use include some intestinal discomfort, which is most common in children, and in the most serious cases, has even been connected to kidney and liver failure. YIKES!
Never fear, there are much safer oils that can be used for teething relief in kids.
Lavender is a great choice and can help with both pain and inflammation. A study done on postoperative pain relief showed that combining lavender essential oil vapor into the oxygen significantly reduced the amount of pain experienced, versus those patients only revived with oxygen after a major surgery.
Black pepper essential oil is also VERY effective at reducing pain and improving circulation plus, it's safe for kids. Because of its warming, anti-inflammatory and antispasmodic properties, black pepper oil works to reduce both pain and inflammation. A 2014 study published in the Journal of Alternative and Complementary Medicine assessed the efficacy of aromatic essential oils on neck pain. When patients applied a cream composed of black pepper, marjoram, lavender and peppermint essential oils to the neck daily for a four-week period, the group reported improved pain tolerance and significant improvement of neck pain.
For inflammation, Roman Chamomile is a wonderful choice and super gentle, even for babies. A study in human volunteers demonstrated that chamomile flavonoids and essential oils penetrate below the surface into deeper skin layers. This is important for their use as topical anti-inflammatory agents that can effectively treat pain.
As an added bonus, lavender and chamomile are excellent oils to help with relaxing and calming your baby so they can rest. Cold wash cloths to chew on can help too. Chamomile is also really great at healing rashes they get from drooling! Just keep those oils out of their mouth! Remember: Teething is temporary. It's tough, but its just a phase. 
Be well, 