Plan B vs Lantus: side-by-side comparison
Plan B (Hormones and Birth Control) and Lantus (Diabetes Treatment) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Plan B | Lantus |
|---|---|---|
| Active ingredient | Levonorgestrel | Insulin Glargine |
| Manufacturer | Foundation Consumer Healthcare | Sanofi |
| Class | Hormones and Birth Control | Diabetes Treatment |
| Strengths | 1.5mg | 100 IU/mL |
| Forms | tablet | pre-filled pen, vial |
What's the same
Plan B and Lantus are used in very different patients, and the points in common are limited. The main shared element is that both meet regulatory standards for efficacy and safety and benefit from pharmacist oversight.
Key differences
Plan B belongs to Hormones and Birth Control while Lantus belongs to Diabetes Treatment. Indications, mechanisms and target populations differ. The comparison is most useful when a clinician has mentioned both medications and the patient wants to understand where each fits.
Mechanism and action
Plan B: Plan B's primary mechanism is delaying or preventing ovulation when taken before the LH surge. Lantus: Insulin glargine binds the insulin receptor with similar affinity to human insulin, activating intracellular signalling that increases glucose uptake in muscle and adipose tissue, suppresses hepatic glucose production an…
When Plan B is preferred
Plan B is indicated for emergency contraception after unprotected intercourse or known/suspected contraceptive failure, in women of reproductive age.
When Lantus is preferred
The medication is indicated in adults and paediatric patients with type 1 diabetes mellitus, and in adults with type 2 diabetes mellitus when basal insulin is required.
Frequently asked questions
Is Plan B or Lantus better? ▾
Plan B and Lantus are not interchangeable — they treat different conditions. Asking which is "better" is meaningful only when a clinician has weighed both for the same specific clinical scenario.
Can I switch from Plan B to Lantus? ▾
Switching between Plan B and Lantus is rarely an appropriate decision since they belong to different classes and treat different conditions. The real question is usually whether the diagnosis calls for one medication or the other — which the prescriber resolves.
Do Plan B and Lantus have the same side effects? ▾
No — they belong to different classes and have distinct side-effect profiles. Each medication has its own prescribing information.
More Plan B comparisons
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.