Mounjaro® Injectable Pen

Mounjaro and Wegovy are two different injectable weight loss medications with differing mechanisms of action.

Wegovy contains the active ingredient semaglutide, which mimics a hormone called GLP-1 to help regulate appetite and slow down stomach emptying.

Wegovy also improves insulin sensitivity, stabilising blood glucose levels and preventing sudden spikes and crashes to prevent excessive hunger signalling by the brain.

Mounjaro contains a different active ingredient, tirzepatide, which also mimics GLP-1, in addition to mimicking another hormone known as GIP to further enhance insulin release by the body.

Mounjaro is not the same as Ozempic. While both medications are prescribed for weight loss, they have different active ingredients and mechanisms of action.

Mounjaro contains tirzepatide, an active ingredient that mimics the gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) hormones. In contrast, Ozempic contains semaglutide, an active ingredient that mimics the GLP-1 hormone, but not the GIP hormone.

Orlistat is a clinically proven oral weight loss treatment that reduces total calorie intake by limiting the absorption of dietary fat.

In contrast, Mounjaro is a weight loss injection that works differently by stabilising blood sugar levels to reduce appetite and slowing stomach emptying, helping you feel fuller for longer.

Mounjaro and Zepbound are both medications containing the active ingredient tirzepatide, which mimics hormones to make the body feel fuller and reduce appetite.

Zepbound is the US name for the same weight loss medication, whereas in the UK, tirzepatide is licensed under the name Mounjaro.

The medications function in the same way and are both prescribed for weight loss and metabolic regulation.

Mounjaro can result in a loss of body fat, which may affect menstrual cycles in some women. This is due to the fact that menstrual cycles are affected by levels of the hormone oestrogen, which is produced by fatty tissues in the body.

Women who experience changes in menstrual cycles from taking Mounjaro are recommended to consult a doctor for further advice.

It is not advisable to take Mounjaro (tirzepatide) during pregnancy, as there is limited data on its safety and impact on developing children.

If you are pregnant or intend to become pregnant and have taken Mounjaro, discuss your usage of this medication with your doctor immediately.

You can buy Mounjaro online in the UK with a prescription from a fully registered and trusted online pharmacy such as Pharmica. Our licensed prescribers and pharmacists can offer clinically proven prescription weight loss treatment, along with personalised advice on diet and exercise, as part of our comprehensive weight management service. We’re proud to be rated the UK’s #1 weight loss service on Trustpilot, having helped thousands of patients successfully achieve their weight loss goals.

To order Mounjaro from Pharmica, simply complete our short medical questionnaire. This will be reviewed by our clinical team to ensure the treatment is safe and appropriate for you. Following approval, your medication will be discreetly delivered to you along with your Pharmica welcome pack.

Should you require any help or support while using Mounjaro, our dedicated customer service team is available to assist you.

• Tirzepatide once weekly for the treatment of obesity, 2022. [Accessed 4th July 2025]
• Electronic medicines compendium: Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen. [Accessed 4th July 2025]
• Eli Lilly & Company: Mounjaro Patient Booklet, 2025. [Accessed 4th July 2025]