The main compound in peppermint oil is menthol. Menthol is in certain OTC remedies, such as vapor rubs, lozenges, and nasal inhalers. Studies show menthol may be more likely to increase congestion than decrease it. Menthol produces a cooling sensation, leading users to believe their nasal passages are clearer and they’re breathing better, even though the passages are still congested.
healthline.com
Thanks for the link. Ravintsara is roughly equal parts camphor and eucalyptol, according to Wikipedia, with less significant amounts of 4 other compounds (linalool, nerolidol, safrole, borneol)