To determine the feasibility of an 8-week fucoidan supplement intervention for patients with fatigue post-cancer treatment and assess changes in fatigue, frailty, and inflammation.

Inclusion Criteria:

• Survivors of cancer
• Age 18 or older
• Speak and understand English
• Have completed surgery, radiation, and/or systemic intravenous anticancer therapy (e.g., chemotherapy, targeted therapy, immunotherapy) ≤10 years prior to enrollment.
• Have a baseline level of fatigue, as determined by reporting a score of 4 or higher for the question, "In the last week, how bad was your worst fatigue on a scale from 0-10?"
• Be willing to commit to the fucoidan supplement dosing and delivery method, to complete evaluation instruments, and to attend all study visits.
• Completed Informed Consent

Exclusion Criteria:

• Current warfarin or other anti-coagulation medication use.
• Current use of supplements that contain fucoidan
• Any allergy to fucoidan
• Be diagnosed with a major psychiatric illness requiring hospitalization within the last year.
• Be diagnosed with dementia.
• Be pregnant or nursing