Claro Law found Pharmac's processes were evidence-based, robust and of a high standard.
But the review noted it would have been preferable if Pharmac had sought further input from its Pharmacological and Therapeutics Advisory Committee and had involved its consumer advisory group.
"We are pleased with the findings, but we are always looking to improve our work.
"This review confirms that we need to focus more on consumer input, improving how we incorporate their views into our decisions," said chief executive Sarah Fitt.
The review highlighted the "significant" role of the media reporting on the brand changes.
Pharmac acknowledged there was work to do in helping the public understand its decision making processes.
"We are keen to work with media to make sure that they are receiving the information they need to report accurately to the public, while also noting the significant responsibility they have in ensuring the public are provided with balanced information that doesn't cause undue concern," Fitt said.