Could a potato reveal how your body handles medicines?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. individuals of both biological sexes, assigned as women or men at birth 2. age: ≥ 18 and ≤ 40 years 3. possesses the ability to understand the study purpose and design 4. contractually capable and provides signed informed consent form 5. in good general health or with mild and/or well-managed conditions such as allergies, asthma, hypertension or orthopedic diseases 6. taking no more than three chronic medications 7. ability to maintain and record a detailed dietary protocol focusing on the consumption of potato-based products for the specified duration of the study 8. individuals classified as either ultrarapid metabolizers (UM), extensive metabolizers (EM), low intermediate metabolizers (LIM) or poor metabolizers (PM) based on their CYP2D6 genotype: Poor Metabolizer (PM, Gen-Score 0): homozygous or compound heterozygous for CYP2D6 \*3, CYP2D6 \*4, CYP2D6\*5, CYP2D6 \*6 Low Intermediate Metabolizer (LIM, Gen-Score 0,25 or 0,5): Homozygous or compound heterozygous for CYP2D6 \*9, \*10, \*41 or compound heterozygous with one allele of CYP2D6 \*3, CYP2D6 \*4, CYP2D6\*5, or CYP2D6\*6 and one allele of CYP2D6 \*17 (0,5) or CYP2D6 \*9, \*10, or \*41 (0,25) Extensive Metabolizer (EM, Gene-Score 2): homozygous or compound heterozygous for CYP2D6 \*1, CYP2D6 \*2, CYP2D6\*35 Ultrarapid Metabolizer (UM, Gen-Score ≥ 3): homozygous or compound heterozygous for CYP2D6 \*1, CYP2D6 \*2, CYP2D6\*35 with at least one allele duplicated or multiplied Exclusion Criteria: 1. BMI \> 30 kg/m2 and \< 18 kg/m2 2. body weight \< 48 kg 3. women: known pregnancy or lactation period; positive urine pregnancy test at screening or kinetic visit 4. men: hemoglobin \< 13 g/dl (8,07 mmol/l) women: hemoglobin \< 12 g/dl (7,45 mmol/l) 5. elevated liver function tests (1 or more of ALAT, ASAT, yGT, Bilirubin \> 2x ULN) 6. reduced renal function (eGFRMDRD \< 60 mL/min/1,7 m2) 7. QTcF \> 450 ms in screening ECG 8. current or recent psychiatric disorders requiring treatment including depression, bipolar disorder, schizophrenia, psychosis or severe anxiety disorders 9. drug dependency at the time of visit 10. use of recreational drugs more than twice a week 11. intake of drugs interfering with CYP2D6 during the past seven days 12. any known hypersensitivity or allergic reactions to yohimbine 13. intake of yohimbine within 48 hours prior to study participation 14. history of hypersensitivity or allergy to potatoes or nightshade vegetables 15. intake of potato-containing meals during the three days before and after eating the potato-rich test meal 16. history of severe hypersensitivity reactions and/or anaphylaxis 17. poor venous conditions that make it impossible to place a peripheral venous catheter and regularly draw blood through it 18. engagement in extreme physical activity within 48 hours prior to study participation