Tirzepatide / Niacinamide Injection

Tirzepatide/Niacinamide Injection is a compounded subcutaneous medication that combines tirzepatide, a dual incretin mimetic, with niacinamide (vitamin B3). Tirzepatide acts as a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. By activating both pathways, it enhances insulin secretion and decreases glucagon release in response to elevated blood glucose, helping to improve glycemic control and support weight management.

Niacinamide, also known as nicotinamide, is a water-soluble form of vitamin B3 included in this formulation for its metabolic and stabilizing properties. It functions as a precursor to coenzymes involved in energy production and supports cellular processes throughout the body. Vitamin B3 plays a role in digestion, nerve function, and skin health, and is essential for converting nutrients into usable energy. In this combination, niacinamide contributes to overall metabolic support while also helping maintain formulation integrity. At a modest dose of 2 mg/mL, it acts as a cofactor without producing the flushing effects associated with higher-dose niacin therapies.

Tirzepatide/Niacinamide Injection is available in multiple strengths to support individualized dosing. The formulation is provided in 17 mg/2 mg per mL and 8 mg/2 mg per mL concentrations, with various vial sizes for flexibility in use. Treatment with tirzepatide typically begins at a low dose and is gradually increased based on patient response and tolerability. This medication is administered as a once-weekly subcutaneous injection. The addition of niacinamide does not alter the dosing schedule.

This product is intended for use under the supervision of a licensed healthcare provider and should be used only with a valid prescription as part of a broader plan for managing blood sugar and weight.

Tirzepatide works by activating two incretin receptors at once. It mimics the actions of both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1), making it a dual incretin, or “twincretin,” therapy. After subcutaneous injection, tirzepatide binds to receptors in pancreatic islet cells and other tissues.

This dual activation triggers insulin release from pancreatic β-cells and reduces glucagon secretion from α-cells, but only when blood glucose levels are elevated. This glucose-dependent mechanism supports both fasting and post-meal blood sugar control. In addition, activation of receptors in the brain and gastrointestinal tract slows gastric emptying and increases satiety. As a result, many patients experience a reduced appetite and a greater sense of fullness, which supports weight reduction over time.

By acting on two complementary hormonal pathways, tirzepatide provides broader metabolic benefits than single-pathway therapies. It improves insulin sensitivity, supports pancreatic function, and promotes healthier blood sugar regulation. Weight loss effects are primarily driven by appetite suppression and reduced caloric intake. Tirzepatide may also influence how the body uses energy and stores fat.

Niacinamide functions in this combination as a metabolic co-factor. It is essential for the formation of NAD and NADP, which are required for numerous enzymatic reactions related to energy production. With adequate niacinamide, cells can efficiently convert nutrients into energy (ATP), helping to meet the metabolic needs of tissues. While it does not directly lower blood glucose, niacinamide supports cellular function and contributes to overall metabolic health.

Tirzepatide/niacinamide injection should not be used in individuals with a personal or family history of medullary thyroid carcinoma (MTC) or those with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Use is also contraindicated in anyone who has experienced a serious hypersensitivity reaction to tirzepatide or any component of the injection, including reactions such as anaphylaxis or angioedema. Individuals with known allergies to similar medications should avoid this therapy to reduce the risk of a severe allergic response.

This injection is not intended for the treatment of type 1 diabetes or diabetic ketoacidosis and should not be used as a substitute for insulin in those conditions. Caution is advised in patients with delayed gastric emptying or other significant gastrointestinal disorders, as tirzepatide can further slow gastric motility and may worsen related symptoms.

Tirzepatide has not been evaluated in individuals with a history of pancreatitis and should be used cautiously in such cases. Similarly, caution is warranted in patients with gallbladder disease, as weight loss may increase the risk of gallstone formation.

In individuals with diabetic retinopathy, rapid changes in blood glucose levels may temporarily affect eye health. Monitoring is recommended for those with a history of diabetic eye disease.

Tirzepatide/niacinamide injection has low potential for pharmacokinetic drug-drug interactions. As a peptide, tirzepatide is broken down into amino acids and does not significantly affect liver enzyme systems involved in drug metabolism. However, its physiological effects can influence how other medications are absorbed or tolerated.

The most notable interaction involves delayed gastric emptying. Tirzepatide slows the rate at which the stomach empties, which can temporarily reduce the absorption of oral medications taken around the same time. This effect is most noticeable after initial doses and tends to decrease with continued use. Medications that require consistent or rapid absorption may be affected. Adjustments in timing or monitoring may be needed for sensitive oral therapies.

Special care should be taken with oral contraceptives. Women using birth control pills should consider an alternative or backup method of contraception when starting tirzepatide or increasing the dose. A non-oral option or barrier method is recommended for at least four weeks after any dose change to prevent reduced contraceptive effectiveness.

Tirzepatide also interacts pharmacodynamically with other medications that lower blood sugar. When used together with insulin or sulfonylureas, the risk of hypoglycemia increases. In such cases, the doses of those medications may need to be reduced, and blood glucose should be monitored closely. Tirzepatide should not be used alongside other GLP-1 receptor agonists, as combining similar agents can increase side effects without added therapeutic benefit.

Tirzepatide/niacinamide injection is generally well tolerated. The most common side effects are gastrointestinal and tend to occur early in treatment or during dose increases. Nausea, decreased appetite, and indigestion are frequently reported. Diarrhea is also common, and a smaller number of individuals may experience vomiting, particularly during dose escalation. These symptoms are usually temporary and tend to improve over time. Gradual dose titration helps minimize discomfort. Constipation, bloating, and a feeling of fullness may also occur, sometimes accompanied by belching or abdominal discomfort.

Outside the gastrointestinal system, other side effects are less common. Mild injection site reactions, such as redness or itching, can occur but typically resolve without intervention. Allergic reactions are rare; however, symptoms like widespread rash, facial swelling, or difficulty breathing require immediate medical attention and discontinuation of the medication.

Tirzepatide does not typically cause low blood sugar when used alone, as it only stimulates insulin release when blood glucose is elevated. However, when combined with other medications that lower blood sugar, such as insulin or sulfonylureas, there is a risk of hypoglycemia. In such cases, patients may need to adjust the doses of those medications. Signs of low blood sugar include shakiness, sweating, dizziness, and confusion, and should be addressed promptly.

Rare but serious side effects may include pancreatitis and gallbladder problems. Patients should seek medical attention if they experience severe or persistent abdominal pain, especially if it radiates to the back or is accompanied by vomiting. Rapid weight loss may increase the risk of gallstones or gallbladder inflammation. Drinking adequate fluids and maintaining a steady rate of weight loss may help reduce this risk. Any new upper abdominal pain or digestive symptoms should be evaluated by a healthcare provider.

In some individuals with long-standing diabetes, rapid improvements in blood sugar may temporarily worsen diabetic eye disease. Any vision changes should be promptly reported and evaluated.

Although thyroid tumors have been observed in animals given high doses of tirzepatide, the relevance to humans remains unclear. As a precaution, patients should inform their healthcare provider if they notice a lump in the neck, changes in voice, or difficulty swallowing.

Pregnancy
Tirzepatide/niacinamide injection is not recommended during pregnancy. The safety of this medication in pregnant individuals has not been established, and its effects on fetal development are unknown.

Blood glucose control is essential during pregnancy, but other treatments with established safety profiles are typically preferred. If pregnancy occurs while taking tirzepatide/niacinamide, the medication should be discontinued unless the expected benefit outweighs the potential risk to the fetus.

Women of childbearing potential who are using this medication should use effective contraception. Because tirzepatide may reduce the effectiveness of oral contraceptive pills, a barrier method or non-oral contraception is advised. If pregnancy is being planned, tirzepatide should be stopped well in advance to allow the medication to clear the body before conception. This helps minimize any exposure during early pregnancy.

The small amount of niacinamide in this injection is unlikely to pose any risk during pregnancy. Niacinamide is a vitamin found in standard prenatal supplements and is required for normal fetal development. However, the primary concern in this combination is the tirzepatide component.

Breastfeeding
The safety of tirzepatide during breastfeeding has not been established. It is not known whether tirzepatide passes into human milk. Due to its large molecular size, any transfer into breast milk is likely to be minimal, and the medication would likely be broken down in the infant’s digestive system. However, because data are lacking, caution is recommended when considering use in nursing mothers.

Tirzepatide/niacinamide injection should generally be avoided during breastfeeding, especially in newborn or premature infants. In cases where glucose control or weight management is needed postpartum, other treatments with a better-established safety profile for lactation may be considered. If tirzepatide is paused during breastfeeding, it can be resumed after weaning.

Niacinamide is a naturally occurring vitamin and is normally present in breast milk. The small amount included in this formulation is not expected to pose any risk to a breastfeeding infant. Even so, the decision to use this medication while breastfeeding should be made based on individual circumstances.

Each case should be evaluated carefully, considering both the needs of the mother and the potential effects on the infant. Treatment choices should be made in coordination with a qualified healthcare provider.

Tirzepatide/niacinamide injection should be stored in a refrigerator between 36°F and 46°F (2°C to 8°C). Keep the vials cold when not in use, and do not allow them to freeze. If a vial freezes, it should be discarded, as freezing may damage the medication. The injection can remain at room temperature briefly during preparation, but extended exposure to warmer temperatures should be avoided.

To protect the medication from light, keep the vials in their original packaging or a covered container inside the refrigerator. Store all medications out of reach of children and pets in a secure location. Before each use, inspect the vial to ensure the solution is clear and colorless to slightly pale yellow. Do not use the medication if it appears cloudy, discolored, or contains particles.

Once the vial is punctured, it becomes a multi-dose container. Always use a new sterile needle and syringe for each dose. Discard any remaining medication 28 days after the first use or by the date on the label, whichever comes first. Mark the date of first use on the vial as a reminder. Do not use the vial beyond the recommended period.

Unused medication should not be poured down drains or flushed. Follow local disposal guidelines. Many pharmacies offer medication take-back programs for safe disposal. Used needles and syringes should be placed in a puncture-proof sharps container and disposed of according to local regulations. Do not place sharps in household trash.