Hi Mel

Most studies have not shown any contraindication for rhodiola with other medicines. However there may be a very mild interaction if you are on antidepressants.
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Contraindications for dandelion extracts:
Obstruction of bile ducts, gallbladder empyema, ileus. In case of gallstones, use only after consultation with a physician.

Side Effects: As with all drugs containing bitter substances, discomfort due to gastric hyperacidity may occur.

Use During Pregnancy and Lactation: No restrictions known.

Interactions with Other Drugs: None
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Grapefruit Extract: Two components found in grapefruit juice, naringin and naringenin**, inhibit production of an enzyme in the intestinal tract, thus increasing the rate of absorption for certain classes of drugs (including some antihistamines, birth control pills, anti-epilepsy medications and some Antibiotics .

In other words...it increases the effects of other drugs.