The Side Effects of Xenadrine Weight Loss Pills

Cytodyne Technologies manufactures several types of weight-loss aids under the name Xenadrine, including Xenadrine Ultra and caffeine-free Xenadrine Ultra. Xenadrine Ultra in both forms differs from previous forms of Xenadrine such as EFX, which contained several sources of caffeine. Cytodyne makes it difficult to evaluate the potential side effects of the drugs because the company does not include the exact doses of each ingredient on the label but lumps them together under the names Ultra Blend and Lipo-Core.


The first ingredient in the Thermodyne blend in Xenadrine Ultra is anhydrous caffeine, which means caffeine with all the water content removed -- in other words, it’s a dehydrated form of caffeine. Caffeine can have positive side effects when you’re trying to lose weight, such as decreasing your appetite, slightly increasing your metabolism and acting as a natural diuretic, which is helpful if you retain fluid 1. On the negative side, caffeine can cause:

  • irritability
  • nervousness
  • muscle twitches
  • jitteriness
  • dizziness
  • nausea
  • restlessness
  • difficulty sleeping
  • tachycardia
  • or rapid heartbeat

Lady's Mantle

The main ingredient listed for the Lipo-Core part of the supplement in both Xenadrine Ultra and caffeine-free Xenadrine Ultra is lady’s mantle, also called frauenmantle. Lady’s mantle can cause liver damage; if you develop jaundice, a yellowish tinge to your skin or whites of your eyes, weakness or fatigue, stop taking Xenadrine. Pregnant or breastfeeding women should not take lady’s mantle, cautions Allina Hospitals and Clinics.

Para-Amino Benzoic Acid

Para-amino benzoic acid, a compound used in sunscreens, is found in both forms of Xenadrine. This compound is not a vitamin, although it has similar actions and is often found in foods that contain B-complex vitamins. Side effects of PABA taken in large amounts include rash, vitiligo, a patchy skin discoloration and liver damage. Daily doses up to 400 mg are considered safe, according to Baptist Health Systems, but the amount of PABA in Xenadrine isn’t published.


Both forms of Xenadrine Ultra also contain phytosterols, plant-derived compounds that have properties similar to cholesterol. Potential side effects of phytosterols include diarrhea, nausea, indigestion or constipation.