---
title: "Metformin Structure (C4H11N5): 3D Model, Formula & Molar Mass | MolDraw"
url: https://www.moldraw.com/molecules/metformin.html
description: "Structure of Metformin (C4H11N5, 129.17 g/mol): rotatable 3D model, 2D skeletal formula, IUPAC name, SMILES, shape, polarity, uses and FAQ."
lang: en
publisher: Scidart Academy
generated: 2026-10-26
---
[MolDraw](https://www.moldraw.com/) › [3D molecule models](https://www.moldraw.com/molecules/) › Metformin structure

# Metformin structure and 3D model (C4H11N5)

Metformin is a biguanide: two guanidine units joined through a shared nitrogen, with two methyl groups on one end. Its many nitrogens make it a strong base.

**Quick answer:** Metformin is **C4H11N5**, molar mass **129.17 g/mol**. Small, nitrogen-rich and very polar; its hydrochloride salt is freely soluble in water.

Atom labels Hydrogens Spin

Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised).

## Metformin at a glance

| Formula | C4H11N5 |
| --- | --- |
| Molar mass | 129.17 g/mol |
| IUPAC name | 3-(diaminomethylidene)-1,1-dimethylguanidine |
| Atoms / bonds | 20 / 19 |
| H-bond donors / acceptors | 3 / 1 |
| logP (estimated) | -1.2 |
| SMILES | `CN(C)C(=N)N=C(N)N` |
| InChIKey | `XZWYZXLIPXDOLR-UHFFFAOYSA-N` |
| PubChem | [4091](https://pubchem.ncbi.nlm.nih.gov/compound/4091) |

![2D structural formula of Metformin (C4H11N5)](https://www.moldraw.com/molecules/img/metformin.svg)

2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/)

## What the 3D model of Metformin shows

The model contains **20 atoms** (9 heavy atoms and 11 hydrogens) joined by **19 bonds**; in ball-and-stick mode every stick is one bond, and double or aromatic bonds are drawn as multiple sticks. Switch to *space-filling* to see the molecule as its electron cloud, scaled to van der Waals radii: this is the shape other molecules actually "feel". It can donate 3 and accept 1 hydrogen bonds, and its estimated logP of -1.2 means it is very water-loving (hydrophilic). Its topological polar surface area is 91 Ų.

## Shape and bond angles

| Atom(s) | Geometry / hybridisation | Angles & lengths |
| --- | --- | --- |
| guanidine carbons | Trigonal planar, sp² | ≈ 120° |
| NH₂ and C=N nitrogens | Near-planar, delocalised | ≈ 120° |
| methyl carbons | Tetrahedral, sp³ | ≈ 109.5° |

### Is Metformin polar?

Yes, very. It has many N–H donors and nitrogen acceptors, and in the body it is almost fully protonated. Its logP is strongly negative.

## Elemental composition of C4H11N5

| Element | Atoms | Mass (g/mol) | Mass % |
| --- | --- | --- | --- |
| Carbon (C) | 4 | 48.044 | 37.20% |
| Hydrogen (H) | 11 | 11.088 | 8.58% |
| Nitrogen (N) | 5 | 70.035 | 54.22% |

Calculated from IUPAC standard atomic weights. Check any formula with the [molar mass calculator](https://www.moldraw.com/tools/free-chem-tools/molar-mass-calculator.html).

## Uses of metformin

- First-line medicine for type 2 diabetes
- Lowers glucose production by the liver
- Studied in research on ageing and cancer

## Interesting facts

- Metformin is related to galegine, a compound from the plant goat's rue (Galega officinalis).
- It is on the World Health Organization's List of Essential Medicines.
- It is made from dimethylamine hydrochloride and dicyandiamide.

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## Frequently asked questions

### What is the structure of Metformin?

Metformin is a biguanide: two guanidine units joined through a shared nitrogen, with two methyl groups on one end. Its many nitrogens make it a strong base. Its SMILES is CN(C)C(=N)N=C(N)N.

### Is metformin a base?

Yes. As a biguanide it is a strong organic base, and it is sold as metformin hydrochloride.

### What does the bi- in biguanide mean?

It means two guanidine groups joined together. Guanidine itself is HN=C(NH₂)₂.

### What is the chemical formula and molar mass of Metformin?

Metformin is C4H11N5 with a molar mass of 129.17 g/mol. It contains 20 atoms: 4 carbon, 11 hydrogen, 5 nitrogen.

### What is the IUPAC name of Metformin?

The IUPAC name is 3-(diaminomethylidene)-1,1-dimethylguanidine.

### How do I draw Metformin?

Open the MolDraw editor, paste the SMILES CN(C)C(=N)N=C(N)N or type "Metformin" in name search, and the structure is drawn for you. You can then export it as PNG, SVG, MOL or CDXML.

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