Ingrezza typically produces measurable improvement within the first two weeks, with about 40% of patients on the standard dose achieving at least a 50% reduction in involuntary movements by week six. But the full effect takes much longer. Maximal effectiveness for tardive dyskinesia develops over roughly 32 weeks of continuous use.
What Happens in the First Few Weeks
You’ll start on 40 mg once daily for the first week, then increase to the recommended 80 mg dose. Clinical trial data from the FDA label shows that patients taking 80 mg began separating from placebo at the week-two mark, meaning involuntary movements were already declining in a measurable way within 14 days of starting treatment.
By week six, the primary endpoint used in the pivotal KINECT 3 trial, 40% of patients on 80 mg had a treatment response, defined as a 50% or greater reduction in their involuntary movement scores. For comparison, only about 9% of patients on placebo hit that same threshold. The lower 40 mg dose also worked, though less dramatically: about 24% of patients responded at that level by week six.
So while some people notice a difference within the first couple of weeks, six weeks is a more realistic benchmark for gauging whether the medication is helping you.
Why Full Results Take Months
Ingrezza works by blocking a protein that packages a brain chemical called dopamine into nerve cells. This gradually reduces excess dopamine signaling that drives the repetitive, uncontrollable movements of tardive dyskinesia. The drug itself is absorbed quickly (peak blood levels occur within about 30 to 45 minutes of a dose) and clears the body with a half-life of around 16 hours. But the downstream effect on movement circuits builds slowly over time.
Maximal improvement for tardive dyskinesia takes up to 32 weeks, or roughly eight months, of continuous daily use. This doesn’t mean nothing happens until month eight. It means that the benefit keeps accumulating week after week, with each month bringing incremental gains on top of the earlier improvement you noticed in the first six weeks.
Long-Term Improvement at 48 Weeks
A year-long extension study called KINECT 4 tracked patients taking Ingrezza for 48 weeks. The results showed substantial, sustained improvement. At the 48-week mark, more than 75% of participants in every dose group rated themselves as “much improved” or “very much improved.” In the 80 mg group specifically, that number reached 89%.
Involuntary movement scores continued to decline throughout the study. Patients on the 80 mg dose saw an average reduction of 11 points on the standard movement rating scale by week 48, a clinically meaningful change that translated to noticeably less facial grimacing, tongue movement, or limb jerking in daily life.
Timeline for Huntington’s Disease Chorea
Ingrezza is also approved for involuntary movements (chorea) associated with Huntington’s disease, and the timeline is shorter for this condition. Maximal effectiveness develops within about 12 weeks. In the KINECT-HD trial, patients on Ingrezza saw their chorea scores drop by 4.6 points compared to 1.4 points for placebo over a 12-week treatment period, a statistically significant difference.
What Happens If You Stop Taking It
Ingrezza controls symptoms rather than curing the underlying condition. In clinical trials, patients who completed 48 weeks of treatment and then stopped during a four-week washout period saw their involuntary movements begin returning toward their original severity. Response rates after the washout were lower than they had been at week eight of treatment. This means that continued daily use is necessary to maintain the benefit, and stopping the medication will likely lead to a gradual return of symptoms.
What to Realistically Expect
The timeline breaks down roughly like this:
- Week 1: Starting dose of 40 mg, then increasing to 80 mg
- Week 2: First measurable reductions in involuntary movements for some patients
- Week 6: Clear treatment response in about 40% of patients on 80 mg
- Weeks 6 through 32: Continued gradual improvement toward peak effectiveness
- Week 48 and beyond: Sustained benefit with ongoing use
If you’ve been taking Ingrezza for a few weeks and feel like it’s not doing much yet, that’s common. The six-week point is a reasonable time to assess early progress with your prescriber, but the medication may continue improving your symptoms for months afterward. The 80 mg dose produced roughly twice the symptom reduction of the 40 mg dose in trials, so if you’re still on a lower dose due to tolerability concerns, adjusting the dose is one variable that can affect how quickly and how much you improve.