How quickly does a vitamin B12 injection relieve numbness and tingling?

The response depends on whether low B12 caused the nerve symptoms, how long the deficiency was present, and whether another condition is contributing. Some people notice an early change in sensation or energy, but tingling may fade unevenly. Nerves can remain irritable after the vitamin level starts to recover, so a slow response does not automatically mean treatment has failed.

Follow the injection schedule prescribed for you and attend any blood-test appointments. Protect numb areas from hot water, heating pads, cuts, and pressure because reduced sensation can hide an injury. Note where symptoms occur, whether they are spreading, and whether balance or strength changes. Read more about [Numbness and Tingling](/symptoms/numbness-and-tingling/) and [Vitamin B12 Injection](/treatments/medical-management/vitamin-b12-injection/).

Seek urgent medical help for sudden one-sided numbness, facial drooping, trouble speaking, severe weakness, new loss of bladder or bowel control, or difficulty walking. Arrange a review if symptoms worsen, affect balance, or do not begin to settle on the plan your clinician gave you; other causes may need checking.

Ask what caused the low B12, when improvement should be reviewed, whether tablets or further injections are needed, and which tests will check the response. Mention medicines, digestive problems, diet, and alcohol use that could affect absorption.