--- title: "Progesterone Structure (C21H30O2): 3D Model, Formula & Molar Mass | MolDraw" url: https://www.moldraw.com/molecules/progesterone.html description: "Structure of Progesterone (C21H30O2, 314.47 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/) › Progesterone structure # Progesterone structure and 3D model (C21H30O2) Progesterone is a steroid hormone with an enone in ring A and an acetyl group at C17. It has no OH groups, only two ketones. **Quick answer:** Progesterone is **C21H30O2**, molar mass **314.47 g/mol**. Rigid steroid skeleton with ketones at each end; non-polar overall and practically insoluble in water. Atom labels Hydrogens Spin Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised). ## Progesterone at a glance | Formula | C21H30O2 | | --- | --- | | Molar mass | 314.47 g/mol | | IUPAC name | (8S,9S,10R,13S,14S,17S)-17-acetyl-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one | | Atoms / bonds | 53 / 56 | | H-bond donors / acceptors | 0 / 2 | | logP (estimated) | 4.7 | | SMILES | `CC(=O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CCC4=CC(=O)CC[C@]34C)C` | | InChIKey | `RJKFOVLPORLFTN-LEKSSAKUSA-N` | | PubChem | [5994](https://pubchem.ncbi.nlm.nih.gov/compound/5994) | ![2D structural formula of Progesterone (C21H30O2)](https://www.moldraw.com/molecules/img/progesterone.svg) 2D structure (skeletal formula) · [Draw it in MolDraw](https://www.moldraw.com/) ## What the 3D model of Progesterone shows The model contains **53 atoms** (23 heavy atoms and 30 hydrogens) joined by **56 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 0 and accept 2 hydrogen bonds, and its estimated logP of 4.7 means it is fat-loving (lipophilic). Its topological polar surface area is 34 Ų. ## Shape and bond angles | Atom(s) | Geometry / hybridisation | Angles & lengths | | --- | --- | --- | | ring carbons (sp³) | Tetrahedral, sp³; chair-shaped 6-rings | ≈ 109.5° | | C3 ketone and C4=C5 alkene | Trigonal planar, sp²; conjugated enone | ≈ 120° | | acetyl C=O carbon | Trigonal planar, sp² | ≈ 120° | ### Is Progesterone polar? Mostly non-polar. The two C=O groups accept hydrogen bonds, but with no OH or NH donors and a large hydrocarbon frame it dissolves in oils, not water. ## Elemental composition of C21H30O2 | Element | Atoms | Mass (g/mol) | Mass % | | --- | --- | --- | --- | | Carbon (C) | 21 | 252.231 | 80.21% | | Hydrogen (H) | 30 | 30.240 | 9.62% | | Oxygen (O) | 2 | 31.998 | 10.18% | 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 progesterone - Female sex hormone that prepares the uterus for pregnancy - Used in hormone therapy and some contraceptives - Precursor of other steroid hormones in the body ## Interesting facts - Progesterone was first isolated in 1934. - Its name comes from pro-gestation, meaning supporting pregnancy. - Russell Marker developed a cheap synthesis from diosgenin found in Mexican yams. **Drawing structures for your notes?** MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams. [Open MolDraw editor](https://www.moldraw.com/) ## Frequently asked questions ### What is the structure of Progesterone? Progesterone is a steroid hormone with an enone in ring A and an acetyl group at C17. It has no OH groups, only two ketones. Its SMILES is CC(=O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CCC4=CC(=O)CC[C@]34C)C. ### How many stereocentres does progesterone have? Six, at C8, C9, C10, C13, C14 and C17. ### Is progesterone a steroid? Yes. It has the four fused rings (three six-membered and one five-membered) that define steroids. ### What is the chemical formula and molar mass of Progesterone? Progesterone is C21H30O2 with a molar mass of 314.47 g/mol. It contains 53 atoms: 21 carbon, 30 hydrogen, 2 oxygen. ### What is the IUPAC name of Progesterone? The IUPAC name is (8S,9S,10R,13S,14S,17S)-17-acetyl-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one. ### How do I draw Progesterone? Open the MolDraw editor, paste the SMILES CC(=O)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CCC4=CC(=O)CC[C@]34C)C or type "Progesterone" in name search, and the structure is drawn for you. 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