Viscous dietary fiber, functional seeds and ginseng roots have individually been proposed for the management of diabetes. We explored whether their co-administration would improve glycemic control in type 2 diabetes beyond conventional therapy. In a randomized, double-blind, controlled trial conducted at two academic centers (Toronto, Canada and Zagreb, Croatia), individuals with type 2 diabetes were assigned to either an active intervention (10g viscous fiber, 60g white chia seeds, 1.5g American and 0.75g Korean red ginseng extracts), or energy and fiber-matched control (53g oat bran, 25g inulin, 25g maltodextrose and 2.25g wheat bran) intervention for 24weeks, while on conventional standard of care. The prespecified primary endpoint was end difference at week 24 in HbA1c, following an intent-to-treat analysis adjusted for center and baseline. Between January 2016 and April 2018, 104 participants (60M:44F; mean ± SEM age 59 ± 0.8 years; BMI 29.0 ± 0.4kg/m2; HbA1c 7.0 ± 0.6%) managed with antihyperglycemic agent(s) (n = 98) or lifestyle (n = 6), were randomized (n = 52 test; n = 52 control). At week 24, HbA1c levels were 0.27 ± 0.1% lower on test compared to control (p = 0.03). There was a tendency towards an interaction by baseline HbA1c (p = 0.07), in which a greater reduction was seen in participants with baseline HbA1c > 7% vs ≤ 7% (- 0.56 ± 0.2% vs 0.03 ± 0.2%). Diet and body weight remained unchanged. The interventions were well tolerated with no related adverse events and with high retention rate of 84%. Co-administration of selected dietary and herbal therapies was well-tolerated and may provide greater glycemic control as add-on therapy in type 2 diabetes. Registration: Clinicaltrials.gov NCT02553382 (registered on September 17, 2015).