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# Regulatory Review Period for Provepharm’s Provayblue
- URL: https://www.fdaweb.com/regulatory-review-period-for-provepharms-provayblue/
- Published: 2018-12-03T12:00:00.000Z
- Updated: 2026-09-15T00:48:07.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5142945

*Federal Register* notice: FDA has determined for patent extension-related purposes the regulatory review period for Provepharm’s Provayblue (methylene blue), indicated for treating pediatric and adult patients with acquired methemoglobinemia. The regulatory review period has been determined to be 415 days, which includes 232 days that occurred during the testing phase and 183 days during the approval phase. To view the notice, click [here](https://www.gpo.gov/fdsys/pkg/FR-2018-11-30/pdf/2018-26035.pdf?ref=fdaweb.com).