The curcuminoids curcumin, demethoxycurcumin and bisdemethoxycurcumin can be found in the rhizome of turmeric (Curcuma longa). Curcumin is widespread used for colouring foods. Based on its natural low bioavailability and the number of its effects on human health, several approaches such as increasing its water solubility or inhibiting its metabolism were taken to improve its bioavailability. Pharmacokinetics of curcumin from various supplements using those different mechanisms have been compared to the one of native curcumin. The investigator's study here will compare the bioavailability of curcumin from eight different curcumin formulations with native curcumin and between themselves. The study will folllow a single dose (in form of curcumin formulations, normalized to 207 mg curcumin), placebo-controlled, randomized, double-blind, nine-armed crossover study design with ≥ 1-week washout periods. Plasma samples will be collected at intervals up to 24 hours after intake. Investigators will compare the pharmacokinetics between the different curcumin formulations and to native curcumin.

Inclusion Criteria:

• Healthy Volunteers with blood chemistry values within normal ranges
• Body mass index in a normal range

Exclusion Criteria:

• Pregnancy or lactation
• Alcohol and or drug abuse
• Use of dietary supplements or any medications except contraceptives
• Any known malignant, metabolic and endocrine diseases
• Previous cardiac infarction
• Dementia
• Blood pressure >140/90 mmHg
• Resting heart rate not within 50 to 90 beats per minute
• Participation in a clinical trial within the past 6 weeks
• Smoking
• Physical activity of more than 5 h per wk