Ashwagandha Pharmacokinetics Study in Older Adults

Safety, Tolerability, and Pharmacokinetics of an Oral Withania Somnifera Product in Older Adults

This study will measure the oral bioavailability and pharmacokinetics of known compounds from a standardized Withania somnifera botanical dietary supplement in healthy older adults.

This is a randomized, double-blind, crossover trial evaluating (a) the pharmacokinetics of withanolides from two doses (240 and 480 mg) of a commercially available Withania somnifera root and leaf extract (Shoden®), (b) the safety and tolerability of these doses over four weeks' use and (c) the feasibility of remotely measuring sleep- and stress-related outcomes in older adults. Participants will be randomized to one of two dose sequence groups. There will be two four-week study periods separated by a two-week washout period. During each study period, participants will attend a 13-hour pharmacokinetics study visit and return for 24- and 48-hour blood and urine collections. After the 48-hour visit, they will continue taking Shoden® at the administered dose (240 or 480 mg) for four weeks, at which time they will return for a follow-up visit.

Inclusion Criteria:

1. Age 65 and older, male and female
2. Body Mass Index (BMI) greater than 17 and less than 35 at screening
3. Sufficient vision and hearing to complete all tests
4. Willingness to discontinue all botanical supplementation for one week prior to and throughout study
5. No known sensitivity to Withania somnifera or any of its derivatives
6. Normal or clinically not significant 12-lead electrocardiogram (ECG) recording
7. Hepatic (ALT, AST, bilirubin), renal (creatinine, estimated GFR), and TSH parameters within normal range
8. Hemoglobin ≥13.0 g/dL or hematocrit ≥39% (males) OR hemoglobin ≥12.5 g/dL or hematocrit ≥38% (females), per FDA recommendations on blood donation
9. General health status that will not interfere with the ability to complete the study
10. Willingness to attend all study visits
11. Willingness to avoid caffeine and xanthine-containing foods or beverages (e.g., coffee, tea, chocolate, caffeine-containing sodas, colas, etc.), as well as grapefruit juice and poppy-containing foods for 48 hours prior to baseline visits
12. Willingness to adhere to special diet (no dairy, grapefruit products, poppy-containing foods, high-fat meals, caffeine, or xanthine-containing foods or beverages) during baseline visits and until after 24-hour visit
13. Mini-Mental State Exam (MMSE) score ≥26

Exclusion Criteria:

1. Current smoking, alcohol, or substance abuse according to DSM-V criteria
2. Participants who are currently pregnant, actively trying to conceive a child, or planning to within three months of study completion
3. Severe aversion to venipuncture
4. Donation of blood within 90 days of screening
5. Participation in drug research study within 90 days of screening
6. Serious health condition (i.e., illness, injury, impairment, or physical or mental condition which requires a) overnight hospitalization or b) continuing treatment that may cause episodic periods of incapacity of more than 3 consecutive days) within 30 days of screening
7. Allergy to nightshade plants (Solanaceae family)
8. Abnormal labs indicating symptomatic and untreated urinary tract infection
9. History of prostate cancer
10. History of kidney transplant
11. Cancer within the last five years, with the exception of non-metastatic skin cancers
12. Comorbid conditions requiring medication such as diabetes, kidney failure, liver failure, hepatitis, blood disorders, hypotension, thyroid disease, respiratory disorders, or cardiovascular disease
13. Presence of sleep apnea, moderate to severe restless leg syndrome, major circadian rhythm changes, or narcolepsy
14. Significant disease of the Central Nervous System (CNS) such as brain tumor, seizure disorder, subdural hematoma, cranial arteritis, or clinically significant stroke
15. Diagnosis of major depression, schizophrenia, bipolar disorder, or other major psychiatric disorder as defined by DSM-V criteria
16. Diseases associated with dementia such as Alzheimer's disease, vascular dementia, normal pressure hydrocephalus or Parkinson's disease