Rapastinel dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Rapastinel is a drip given for depression.
Evidence grade for Rapastinel: Strong. The rule: at least two finished studies in people, and at least 1,000 people who took it. The sum on this page: 5 completed trials, 2,614 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 2,614
- Human studies
- 5
- Found nothing
- 1
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
5 completed trials, 2,614 people given it
No first-hand reports gathered yet. That is a gap in what we have collected, not a finding that nothing has been reported.
Goal pages: Brain, memory and mood, Sleep
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Rapastinel is a drip that was tested for depression. It works on the same brain switch as ketamine, but more gently. The hope was fast relief without ketamine's spaced out feeling. It failed its big trials and was dropped.
What people take it for
- Fast relief from depression that has not lifted on other drugs.
- A ketamine-like effect without feeling detached.
- Some sell it as a brain booster. No study has tested that.
What studies in people showed
The large trials found nothing. Three trials with 465, 658 and 429 people added a weekly drip to their usual antidepressant. After 3 weeks, people on the dummy drip did just as well. A year long trial in 1,304 people found it did not stop depression coming back. The company stopped the whole programme in July 2019. It all started with a 116 person study. There, one drip eased depression within 2 hours, and it lasted about a week. That early win did not hold up. In 107 healthy people, it did not hurt driving in a simulator. Ketamine did.
What people report
Reports, not study results
The good
- It did not hurt driving in a simulator in 107 healthy people.
- No trial reported hallucinations or feeling detached.
The bad
- In the large trials, people on a dummy drip did just as well.
- Every human study gave it as a drip. Nobody has tested it by mouth or nose spray.
Where these come from: From the trials on this page. We have not collected user reports on this one yet.
My bottom line
My opinion: this is the clearest lesson on the site. One small good study, then about 1,500 people and nothing. If you are struggling with depression, work with a doctor on treatments that held up.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Rapastinel has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Mood and anxiety1,087 people · 3 studies
35 of the 36 indexed goals have no study of any kind behind Rapastinel
No study in people, animals or cells on this page reports a result for these. That does not prove Rapastinel does nothing for them. It does mean anything you have heard about Rapastinel and one of these did not come from a study cited here.
Show full evidence
What is Rapastinel?
Rapastinel is a drip given for depression. In a 116 person study, it lowered depression scores within hours. Then it failed three large final-stage trials in about 1,500 people. People on the dummy drip did just as well. The gaps between groups were a point or less on the depression score. Allergan stopped the programme in July 2019.
Rapastinel is a peptide made of four amino acids. It works on the NMDA receptor, a brain switch that ketamine also works on, but in a gentler way. Naurex and then Allergan developed it as a fast acting antidepressant without ketamine's spaced out, detached feeling.
The large trials are fully reported, but only on the trial registry, never in a journal. In three trials, called RAP-MD-01, 02 and 03, 465, 658 and 429 people with major depression got a weekly drip of rapastinel or a dummy drip. They kept taking their usual antidepressant. After 3 weeks, depression scores fell 5.0, 4.9 and 4.1 points on the dummy. On rapastinel 450 mg they fell 4.7, 5.4 and 5.1 points. The gaps were 0.3, 0.5 and 1.0 points. None was bigger than chance would explain. A year long trial in 1,304 people found it did not delay relapse. Four more large trials of rapastinel on its own were stopped in July 2019. The company's stated reason was a business decision to end the programme. Roughly 3,900 people joined these large trials, plus 617 more in a long term safety follow on.
The early study that started it all was smaller. It had 116 people whose depression had not lifted on a standard antidepressant. One drip of 5 or 10 mg/kg lowered depression scores within 2 hours. The effect lasted about a week. Nobody had hallucinations or felt detached. Doses of 1 and 30 mg/kg did nothing. When the middle doses work and the low and high ones do not, drug makers treat it as a warning sign.
Rapastinel was never approved, and work on it has ended. On this site it is the clearest case of a fast acting antidepressant that looked great in 116 people and vanished in 1,500.
How does Rapastinel work?
In people, here is what is known. One drip of 5 or 10 mg/kg eased depression for about a week in a 116 person study. Weekly 450 mg doses did no better than a dummy in three large trials. In 107 healthy people, doses of 900 and 1,800 mg did not hurt driving in a simulator, while ketamine at 0.5 mg/kg did. Nobody has shown that rapastinel changes NMDA signals in a human brain. In animals and in a dish, rapastinel sticks to the NMDA receptor near the spot where glycine, a helper molecule, binds. At low amounts it boosts the receptor's signal. At high amounts it dampens it. That is the proposed reason only the middle doses worked in the early human study. Rodents showed the same pattern. In rodents, one dose quickly raised proteins at nerve connections and gave a long lasting antidepressant-like effect. That looks like ketamine, but without ketamine's way of plugging the receptor. In a 2022 rodent study it also sped recovery from morphine withdrawal and cut relapse to drug seeking.
What have studies in people found about Rapastinel?
A lot of people. Roughly 3,900 joined the large final-stage trials alone, plus 617 in a long term safety follow on. The company posted results or reasons for stopping for these trials on ClinicalTrials.gov. The results show no benefit. No result from the large trials was ever published in a journal.
- Relapse trial (NCT02951988): 1,304 people over a year. It did not delay relapse on either dosing schedule.
- Four trials of rapastinel on its own, 1,082 people in total, were stopped in July 2019. The company's stated reason was a business decision to end the programme. One more was pulled before anyone joined.
- RAP-MD-02 (NCT02943564): 658 people. Depression scores fell 4.8 points on 225 mg, 5.4 on 450 mg and 4.9 on the dummy drip.
- RAP-MD-01 (NCT02932943): 465 people. Scores fell 4.7 points on the drug and 5.0 on the dummy drip at 3 weeks.
- RAP-MD-03 (NCT02943577): 429 people. Scores fell 5.1 points on the drug and 4.1 on the dummy drip. The 1.0 point gap was within chance.
- Early study (2015): 116 adults whose depression had not lifted on other drugs, one drip. 5 and 10 mg/kg lowered depression scores from day 1 to day 7, starting within 2 hours. 1 and 30 mg/kg did not. Naurex paid.
- Earlier study (NCT01234558): 115 people, one drip, finished 2012, no results posted.
- Driving study (2022): 107 healthy adults. Rapastinel at 900 and 1,800 mg did not hurt simulated driving. Ketamine did. Allergan paid.
What this does not tell you: The large trials answer the main question. A weekly drip of rapastinel added to an antidepressant did no better than a dummy. What they cannot tell you is why the 116 person study looked so different. That study dosed by body weight and found only the middle doses worked. The large trials used a fixed 450 mg dose. No published analysis squares the two. The registry numbers are the company's own tables, never checked by outside scientists. Nothing here tells you about rapastinel by mouth or nose spray, which has never been tested in people. It says nothing about thinking or memory in healthy people either, which no trial measured.
The state of the research
Read this one when someone tells you a small good study settles a question. Naurex paid for the 116 person study and published it. Allergan, which Naurex became part of, then paid for ten registered large trials with several thousand people. That is exactly what should happen after a promising early result, and it gave a clear answer. The results posted in late 2019 and 2020 show gaps of 0.3, 0.5 and 1.0 points on the depression score in the three short trials. They show no difference in relapse. The trials of rapastinel on its own were stopped in July 2019, each marked as a business decision to end the programme.
Two things stand out. First, the large trial results exist only on ClinicalTrials.gov. The company met its legal duty to post them and never published a paper. So the failure is on record, but anyone who only searches journals will miss it. In the journals, the last human paper on whether it works is the good 2015 study. Second, the driving study came out in 2022, after the programme ended. It is a real, well run finding about a drug nobody will take. It shows rapastinel did not hurt driving where ketamine did, which was the whole safety point of the drug. Rapastinel is finished. Vials sold as GLYX-13 claim to hold a compound its own maker tested in several thousand people and found no better than a dummy.
The evidence, in charts
Fig. 1a · how many people
2,614people, across 5 studies in people cited here
| Study | People | Share |
|---|---|---|
| NCT02951988, ClinicalTrials.gov, Naurex / Allergan 2016 | 1,304 | 50% |
| NCT02943564, ClinicalTrials.gov, Naurex / Allergan 2016 | 658 | 25% |
| NCT02943577, ClinicalTrials.gov, Naurex / Allergan 2016 | 429 | 16% |
| Journal of Psychiatric Practice 2015 | 116 | 4% |
| Clinical and Translational Science 2022 | 107 | 4% |
One study holds 50% of these people, so the total rests more on one study than its size suggests. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
All 7 sources here are studies in people.
- Study in people · done in people7100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 4 different years, 2015 to 2022, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- Not on file
- Half-life
- None on file
- Chain length
- None on file
No amino acid sequence is on file for Rapastinel, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2015Randomized proof of concept trial of GLYX-13, an N-methyl-D-aspartate receptor glycine site partial agonist, in major depressive disorder nonresponsive to a previous antidepressant agent
A single drip lifted depression within hours, in the study that started the excitement. One hundred and sixteen adults whose depression had not responded to an antidepressant got one infusion at one of four strengths, or a dummy. The two middle strengths lowered depression scores from the first day through the end of the week. The lowest and highest strengths did nothing. Nobody felt detached or hallucinated. This was an early look at a single dose, not a test of lasting benefit. The maker paid.
116 adults with major depression who had not responded to at least one antidepressant in the current episode, randomised to a single intravenous dose of 1, 5, 10 or 30 mg/kg or placebo. The 5 and 10 mg/kg doses reduced HAM-D17 scores from day 1 through day 7, with onset within 2 hours on the Bech-6; 1 and 30 mg/kg did not. No psychotomimetic effects. Funded by Naurex, the developer.
- Study in people2016A Study of Rapastinel as Adjunctive Therapy in Major Depressive Disorder, RAP-MD-01 (NCT02932943)
Tested properly in a large trial, and it did not work. Four hundred and sixty five adults with depression got a weekly drip of rapastinel or a dummy on top of their usual antidepressant. After three weeks, depression scores had fallen by the same amount in both groups. If anything the dummy group did slightly better. The company posted the figures in 2019 and never published them in a journal. The company paid for the trial.
Phase 3, 465 enrolled, weekly intravenous rapastinel 450 mg or placebo added to an antidepressant. Posted results: MADRS change at 3 weeks of -4.7 on rapastinel versus -5.0 on placebo, least squares mean difference 0.3 (95% CI -1.07 to 1.72), p = 0.65. Sponsor funded; results posted October 2019, never published in a journal.
- Study in people2016A Study of Rapastinel as Adjunctive Therapy in Major Depressive Disorder, RAP-MD-02 (NCT02943564)
A second large trial, two doses instead of one, and the same answer. Six hundred and fifty eight adults with depression got rapastinel at a lower or a higher weekly dose, or a dummy drip. After three weeks all three groups had improved by about the same amount. Neither dose pulled away from the dummy. The company posted the figures at the end of 2019. The company paid for the trial.
Phase 3, 658 enrolled, rapastinel 225 mg, 450 mg or placebo weekly. Posted results: MADRS change at 3 weeks of -4.8 (225 mg), -5.4 (450 mg) and -4.9 (placebo); p = 0.89 for 225 mg versus placebo and p = 0.58 for the 450 mg comparison. Sponsor funded; results posted December 2019.
- Study in people2016A Study of Rapastinel as Adjunctive Therapy in Major Depressive Disorder, RAP-MD-03 (NCT02943577)
A third large trial, and a third failure. Four hundred and twenty nine adults with depression got a weekly drip of rapastinel or a dummy. Depression scores fell a little further on the drug after three weeks. The gap was small enough that chance alone routinely produces gaps that size. The company posted the figures in late 2019. The company paid for the trial.
Phase 3, 429 enrolled, rapastinel 450 mg or placebo weekly. Posted results: MADRS change at 3 weeks of -5.1 versus -4.1, least squares mean difference -1.0 (95% CI -2.70 to 0.68), p = 0.24. Sponsor funded; results posted November 2019.
- Study in people2016A Study of Rapastinel as Adjunctive Therapy in the Prevention of Relapse in Patients With Major Depressive Disorder (NCT02951988)
The largest trial of this drug ran for a year and found nothing. One thousand three hundred and four adults whose depression had lifted took rapastinel weekly, took it every other week, or took a dummy. The drug did not delay relapse on either schedule. Thoughts of suicide were recorded in all three groups, including the dummy group. A trial this size would have found a real benefit if one existed. The company paid for it and posted the figures in 2020.
Phase 3, 1,304 enrolled, 52 week double blind relapse prevention with rapastinel 450 mg weekly, every two weeks, or placebo. Posted results: no difference in time to first relapse, p = 0.53 (every two weeks) and p = 0.46 (weekly). Suicidal ideation was recorded in 17, 25 and 23 participants respectively. Sponsor funded; results posted March 2020.
- Study in people2018Study of Rapastinel as Monotherapy in Patients With MDD (NCT03560518)
The company shut the whole programme down. This trial had enrolled four hundred and thirty nine adults before it stopped in July 2019, and the reason given was a business decision. Three more large trials were halted with the same wording, and a fifth never enrolled anyone. Around a thousand people took part in studies that were then abandoned. No results were reported from any of them. The earlier trials had already failed, which is the context this decision sits in.
Phase 3 monotherapy trial, 439 enrolled, terminated in July 2019. Sponsor's stated reason: business decision to stop the program. Three further phase 3 trials (NCT03614156, 363 enrolled; NCT03668600, 230; NCT03675776, 50) were terminated with the same wording and one (NCT03855865) was withdrawn before enrolling.
- Study in people2022A randomized, multicenter trial assessing the effects of rapastinel compared to ketamine, alprazolam, and placebo on simulated driving performance
Rapastinel left people able to drive. Ketamine did not. One hundred and seven healthy adults each tried every option in turn on separate days, without knowing which was which. They drove in a simulator after a drip of rapastinel at two high doses, after ketamine, after a sedative, or after a dummy. Rapastinel made no difference to their driving. Ketamine impaired it for at least an hour and three quarters. This was a safety question in healthy people, not a test of depression. The maker paid.
107 healthy adults, five period crossover: rapastinel 900 and 1,800 mg intravenously did not impair simulated driving compared with placebo (p > 0.5), while ketamine 0.5 mg/kg did (p = 0.0001) for at least 105 minutes. Funded by Allergan; several authors were Allergan employees.
Where to buy Rapastinel
No seller we track lists Rapastinel yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has Rapastinel been tested in people?
Yes. 2,614 people given it across 5 completed trials cited here, 1 of which found nothing. Rapastinel is a drip given for depression.
What is the Rapastinel dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 5 completed trials, 2,614 people given it
Is Rapastinel FDA-approved?
Not FDA approved. Its final-stage studies in major depression missed their main goals (results posted on ClinicalTrials.gov 2019 to 2020). The company stopped them in July 2019. No further work on it.
Did rapastinel fail its phase 3 trials?
Yes, and the results are public. In RAP-MD-01, 02 and 03, the depression score fell 4.7 to 5.4 points on rapastinel after 3 weeks. It fell 4.1 to 5.0 points on the dummy drip. The gaps were 0.3, 0.5 and 1.0 points, all within chance. The 1,304 person relapse trial found no difference either. These numbers come from the company's own postings on ClinicalTrials.gov. No journal paper was ever published.
But the early trial was positive?
It was. In 116 people, one drip of 5 or 10 mg/kg lowered depression scores within 2 hours, and the effect lasted about a week. Nobody felt detached or spaced out. Doses of 1 and 30 mg/kg did nothing. That result did not hold up in the large trials. Nobody has published an explanation for the gap.
Was rapastinel safer than ketamine?
On the one thing tested head to head, yes. In 107 healthy people, rapastinel drips at 900 and 1,800 mg did not hurt simulated driving. Ketamine at 0.5 mg/kg did, for at least 105 minutes. No rapastinel trial reported hallucinations or feeling detached. But dodging ketamine's side effects is not the same as working like ketamine for depression. The large trials show it did not.
Is GLYX-13 sold as a nootropic worth anything?
No human study has measured thinking or mood in healthy people on rapastinel. Every human trial gave it as a drip. Nobody has tested this four amino acid peptide taken by mouth or nose in people at all. The one large set of data shows it did nothing for depression at the dose the company chose.