| Cover | Oct. 30, 2023 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 30, 2023 |
| Entity File Number | 001-41173 |
| Entity Registrant Name | NEXGEL, INC. |
| Entity Central Index Key | 0001468929 |
| Entity Tax Identification Number | 26-4042544 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 2150 Cabot Boulevard West |
| Entity Address, Address Line Two | Suite B |
| Entity Address, City or Town | Langhorne |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19067 |
| City Area Code | (215) |
| Local Phone Number | 702-8550 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Common Stock, par value $0.001 | |
| Title of 12(b) Security | Common Stock, par value $0.001 |
| Trading Symbol | NXGL |
| Security Exchange Name | NASDAQ |
| Warrants to Purchase Common Stock | |
| Title of 12(b) Security | Warrants to Purchase Common Stock |
| Trading Symbol | NXGLW |
| Security Exchange Name | NASDAQ |
