The short answer
Pharmacologic niacin may weaken glucose lowering during NovoLog Mix70/30 treatment. Its label supports closer monitoring, while the effect cannot be assigned to insulin aspart protamine alone.
What this answer covers
Oral niacin, especially pharmacologic nicotinic acid; ordinary dietary vitamin B3 and nicotinamide differ. Fixed70/30 product contains protamine and soluble aspart.
- Supplement or preparation
- Niacin
- Medication ingredient
- insulin aspart protamine, human
The exact combination label names niacin
NovoLog Mix70/30 lists niacin among agents that may decrease its glucose-lowering effect. More monitoring and clinician-directed treatment review may be needed.
Clinical evidence involves a high-dose combination
A large trial of extended-release niacin plus laropiprant reported more serious diabetes-control disturbances. It was not a trial of this insulin premix, and the coingredient limits attribution of every outcome to niacin alone.
Ingredient and dose boundaries matter
The trial does not show the same risk from ordinary dietary vitamin B3 or every nicotinamide preparation. The insulin label also describes the whole fixed premix, not an isolated protamine component.
Review starting or stopping
Discuss pharmacologic niacin changes with the diabetes team and review glucose readings. Do not increase or decrease insulin independently. No short spacing interval is established to prevent a systemic glucose effect.
Evidence and practical considerations
Side effects & toxicity
Current fixed-combination label explicitly names niacin; precaution applies to the whole premix with no isolated protamine-component attribution.
- Exact scope
- Oral niacin, especially pharmacologic nicotinic acid; ordinary dietary vitamin B3 and nicotinamide differ. Fixed70/30 product contains protamine and soluble aspart. with Insulin aspart protamine human RxCUI352385 IN as part of NovoLog Mix70/30, SC only.
- Medication form and route
- subcutaneous insulin premix; oral supplement
What remains uncertain
- Combination label cannot isolate protamine component; no exact herb-event rate or universal adjustment.
Factors that may matter: Fixed component ratio; Meals; Preparation; Dose; Other glucose-active treatment.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Adults prescribed the fixed insulin-aspart premix
Hypoglycemia can be severe; niacin can reduce glucose lowering. Fixed ratio does not permit independent basal/prandial adjustment. Dose within15minutes before meal start; type2 patients may also dose after meal start as labeled.
How this applies: Exact RxCUI352385 IN insulin aspart protamine, human, addressed as component of this labeled fixed combination.
Combination-product evidence cannot isolate the protamine component or represent pure soluble aspart, NPH or other premixes. No herb-specific event rate.
Source 2: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 25,673high-vascular-risk adults.
High-dose niacin-laropiprant increased serious disturbances in diabetes control compared with placebo.
How this applies: Indirect for insulin aspart protamine as part of NovoLog Mix70/30; original preparation, drug and endpoint retained.
High-dose niacin plus laropiprant, not ordinary nutritional niacin; no exact insulin-premix analysis or protective spacing demonstrated.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Prepared exact protamine-aspart ingredient article with fixed-combination and clinical endpoint limits. | |
| Research summary published |
Article revision: 6c8e6d0e9550086a
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.