Semaglutide Dosage Calculator

What is Semaglutide?

Semaglutide is a synthetic glucagon-like peptide-1 (GLP-1) receptor agonist with 94% structural homology to native human GLP-1. It activates GLP-1 receptors in the pancreatic beta cells (increasing glucose-dependent insulin secretion), hypothalamus (suppressing appetite and food reward), and gastric smooth muscle (slowing gastric emptying). The STEP 1 trial (Wilding et al., NEJM, 2021) demonstrated a mean body weight reduction of 14.9% over 68 weeks at 2.4 mg/week versus 2.4% for placebo — the largest placebo-controlled weight loss effect documented for any non-surgical intervention. FDA has approved subcutaneous semaglutide as Wegovy (2.4 mg/week) for chronic weight management and Ozempic (0.5–2 mg/week) for type 2 diabetes. An oral formulation (Rybelsus, 7–14 mg/day) is approved for type 2 diabetes only. Semaglutide is a Schedule IV prescription medication — it cannot legally be obtained without a valid prescription and physician supervision.

How to Take Semaglutide

**Standard titration schedule (subcutaneous injection, weekly):** - **Weeks 1–4:** 0.25 mg once weekly (initiation dose — not therapeutic, allows GI adaptation) - **Weeks 5–8:** 0.5 mg once weekly - **Weeks 9–12:** 1.0 mg once weekly - **Weeks 13–16:** 1.7 mg once weekly - **Week 17 onward:** 2.4 mg once weekly (maintenance for weight loss) For type 2 diabetes (Ozempic), the maintenance dose is typically 0.5–2.0 mg/week, titrated more slowly based on glycaemic response. Dose escalation should only proceed if the previous dose is tolerated — GI side effects are the primary dose-limiting factor. If nausea is severe at any step, hold the dose for an additional 4 weeks before escalating.

Timing Recommendations

Administer once weekly on the same day each week, at any time of day, with or without food. Subcutaneous injection sites: abdomen (preferred), upper thigh, or upper arm. Rotate sites weekly to prevent lipodystrophy. If a weekly dose is missed by < 5 days, inject as soon as possible. If > 5 days have passed, skip and resume on the next scheduled day.

Potential Side Effects & Safety

Nausea is the most common side effect (44% of patients in STEP 1), followed by diarrhoea (30%), vomiting (24%), and constipation (24%). These are dose-dependent, peak during dose escalation, and typically resolve within 4–8 weeks. Eating smaller meals, avoiding high-fat foods, and staying hydrated substantially reduces GI symptoms. Rare but serious: acute pancreatitis (discontinue immediately if persistent severe abdominal pain occurs), gallbladder disease (cholelithiasis), and potential thyroid C-cell tumour risk (black-box warning based on rodent data; clinical significance in humans at therapeutic doses is not established but contraindicates use in MEN-2 syndrome).

Best Stacks with Semaglutide

Semaglutide is not typically combined with other GLP-1 agonists or DPP-4 inhibitors (redundant mechanism). For metabolic health support, physicians may co-prescribe berberine or metformin for insulin sensitisation at lower semaglutide doses. Adequate protein intake (≥ 1.2 g/kg/day) and resistance training are essential to preserve lean mass during the rapid weight loss semaglutide produces.

Scientific References

All dosage recommendations are grounded in peer-reviewed research.

1. 1
   Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1 Trial)

   New England Journal of Medicine · 2021

2. 2
   Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6)

   New England Journal of Medicine · 2016