Key benefits of fennel include:

• Digestive Health: Fennel has long been used to support digestive health. It can help relieve symptoms of indigestion, such as bloating, gas, and stomach cramps. It has been shown to have antispasmodic properties, helping to relax the muscles in the gastrointestinal tract and promote smoother digestion. Fennel can also help some serious digestive conditions such as necrotizing enterocolitis.

• Hormonal Balance: Fennel contains phytoestrogens, which are plant compounds that mimic the activity of oestrogen in the body. These compounds can help regulate hormone levels and alleviate symptoms associated with hormonal imbalances, such as menstrual irregularities and menopausal symptoms.

• Respiratory Health: Fennel has expectorant properties, which means it can help loosen mucus and phlegm in the respiratory tract. It has been used traditionally to relieve coughs, congestion, and respiratory conditions like bronchitis. Fennel can have bronchodilatory effects, benefiting individuals with asthma.

• Breast Milk Production: Fennel has been used as a galactagogue, a substance that promotes breast milk production in lactating women. Fennel can have a positive effect on milk production and can be helpful for breastfeeding mothers.

• Blood Sugar Regulation: Fennel can help regulate blood sugar levels and has hypoglycaemic effect, aiding in the management of diabetes. 

• Memory Enhancement and Stress Relief: Fennel has been shown to have memory enhancement properties. It is also thought to help ease stress and promote feelings of relaxation.

Avoid combining fennel with the following medications:

• Oestrogen-Based Medications: Fennel contains compounds that may have oestrogen-like effects in the body. Concurrent use with oestrogen-based medications, such as hormone replacement therapy (HRT), tamoxifen, or oral contraceptives, could potentially enhance oestrogenic effects, leading to hormonal imbalances or adverse effects. Monitor for signs of oestrogenic side effects and consult with a healthcare provider.

• Anticoagulant Medications: Fennel may have mild blood-thinning effects. Combining it with anticoagulant medications such as warfarin or aspirin could increase the risk of bleeding. Monitor for signs of bleeding and consult with a healthcare provider.

• Cyclosporine: Fennel may interact with cyclosporine, a medication commonly used to prevent organ rejection after transplant surgery or to treat autoimmune diseases. Concurrent use of fennel with cyclosporine could potentially alter drug metabolism or effectiveness. Consult with a healthcare provider before using fennel if you are taking cyclosporine.

• Diuretic Medications: Fennel may have diuretic effects, increasing urine production. Concurrent use with diuretic medications could lead to excessive diuresis and electrolyte imbalance. Monitor fluid and electrolyte levels closely and consult with a healthcare provider.

• Antidiabetic Medications: Fennel may affect blood sugar levels. Concurrent use with antidiabetic medications could enhance the effects, leading to hypoglycemia (low blood sugar levels). Monitor blood sugar levels closely and consult with a healthcare provider.

• Ciprofloxacin: Fennel may interact with ciprofloxacin, a fluoroquinolone antibiotic commonly used to treat bacterial infections. Concurrent use of fennel with ciprofloxacin could potentially interfere with the absorption or effectiveness of the antibiotic. It's advisable to avoid consuming fennel while taking ciprofloxacin or to separate the intake of fennel and the antibiotic by several hours to minimise potential interactions.

Individuals with the following allergens or medical conditions should use caution or avoid fennel:

• Allergies to Celery, Carrots, or Mugwort Pollen: Fennel belongs to the Apiaceae family, which includes celery and carrots. Some individuals with allergies to these foods may also experience allergic reactions to fennel. Additionally, fennel pollen can cross-react with mugwort pollen, triggering allergic symptoms in susceptible individuals. Symptoms may include skin rash, itching, swelling, or respiratory issues such as difficulty breathing. Use fennel cautiously if you have known allergies to celery, carrots, or mugwort pollen.

• Pregnancy: Fennel contains compounds that may have estrogen-like effects in the body. While fennel has traditionally been used to promote lactation in breastfeeding mothers, it may also have uterine-stimulating properties and could potentially lead to complications during pregnancy. Pregnant individuals should avoid consuming large amounts of fennel, especially in medicinal forms, to prevent adverse effects.

• Hormone-Sensitive Conditions: Fennel contains compounds that may have estrogen-like effects, which could potentially exacerbate hormone-sensitive conditions such as breast cancer, ovarian cancer, endometriosis, or uterine fibroids. Individuals with these conditions should use caution when consuming fennel and consult with a healthcare provider.

• Gastrointestinal Disorders: Fennel may exacerbate gastrointestinal issues such as gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), or peptic ulcers in some individuals. The volatile oils in fennel can stimulate gastric acid secretion or cause gastrointestinal irritation. If you have these conditions, monitor your symptoms and consider avoiding fennel if it worsens your gastrointestinal symptoms.

• Bleeding Disorders: Fennel may have mild blood-thinning effects. Individuals with bleeding disorders or those taking anticoagulant medications should use fennel cautiously, as it could potentially increase the risk of bleeding. Monitor for signs of bleeding and consult with a healthcare provider.