Sweet fennel essential oil is extracted from crushed seeds by steam distillation, and the oil yield is between 2 to 4%. Bitter fennel oil cannot be used in aromatherapy. It is extracted from crushed seeds or whole plants. The main chemical components of fennel essential oil are pine terpenes or pinene, myrcene, fenchone, anethole, methyl piperonol, limonene, cineole and anisaldehyde.
 
 Skin curative effect: It can improve loose skin and enlarged pores. It has the effect of firming and removing fine lines. It has a good moisturizing effect.  It is also helpful to prevent wrinkles or cellulite.
 
 Suitable essential oils: geranium, lavender, rose and cedar.
 
 Note: It is advisable to use a low dose, otherwise it will make people dizzy, and should not be used during pregnancy or when menstrual cramps occur, because parsley can cause uterine contractions. It is said to stimulate and regulate the kidneys, but avoid using it when suffering from kidney disease and gastric ulcer.