NR-004
Ingredient Atlas entry · Compound
Acetyl-L-carnitine
A form of carnitine that the body makes and red meat supplies
A form of carnitine, made in the body and found mainly in red meat, studied mostly for nerve function and thinking skills, often in older adults or people with a long-term condition. Here is every study in people we could find, sorted from each study's summary.
- Found in: red meat
- Most tested: 3,000 mg a day
- Often taken for 3 months or more
The research map
From every paper to the studies that matter
Much of the research on acetyl-L-carnitine is lab and animal work. Only a small share tests it in people, and that is what this page is about.
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2,750 papers mention acetyl-L-carnitine. Every record in PubMed, all years
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283 are about people. The rest: 1,344 lab and animal studies, 274 reviews, 849 on chemistry, farming and more
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160 give acetyl-L-carnitine on its own. 68 more test it with other ingredients or inside a blend
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61 are randomised against a placebo. The strongest kind of study
Bar lengths use a square-root scale so the small numbers stay visible.
At a glance
How much research there is
- 160 studies giving acetyl-L-carnitine to people
- 61 of them randomised against a placebo
- 11,753 people taking part, where studies say
- 79 systematic reviews pooling the trials
Studies in people, by year published
Acetyl-L-carnitine on its own.
Randomised, placebo-controlled
Other designs
What was measured
What the studies looked at
Each study can measure several things. Choose a topic to see its studies in the list below.
Studies in people with a diagnosed condition are counted here and listed with their population. We describe what they measured, not what they might treat. Most studies also report safety; see below.
Doses and extracts
What was tested, and how much
Acetyl-L-carnitine is a single compound, so milligrams compare directly from one study to the next. Most studies gave it by mouth every day for weeks or months, and some gave it by injection or drip.
Daily amount, one dot per study
Summary read72 studies don't give a daily amount in their summary and aren't shown.
Studies per extract
Named extracts are the maker's brand. "Not named" means the study didn't say.
Every study
All studies in people
Filter the list, then open a study on PubMed. Each row comes from the study's published summary.
| Study | Who took part | People | Extract and daily dose | Length |
|---|---|---|---|---|
| Schweiger 2025Single-arm or open-label | Adults with fibromyalgia | 183 | Not named | – |
| Krims-Davis 2025Pharmacokinetic | Healthy volunteers | – | Not named, 1,500 mg | – |
| Lee 2024RCT, active or other control | Patients with cognitive decline taking donepezil | 119 | Not named | 24 weeks |
| Sassi 2023Observational | Adults with ALS, matched controls | 90 | Not named | 104 weeks |
| Grossini 2023Single-arm or open-label | Newly diagnosed ALS patients, healthy controls | 32 | Not named | 26 weeks |
| Malaguarnera 2022RCT, placebo | Prefrail older adults | 92 | Not named, 3,000 mg | 12 weeks |
| Mazdeh 2022RCT, placebo | Acute ischemic stroke patients | 69 | Not named, 3,000 mg | 0 weeks |
| Tauqir 2021RCT, placebo | Women with polycystic ovary syndrome | 147 | Not named, 3,000 mg | 12 weeks |
| Curran 2019RCT, placebo | Adults with severe carpal tunnel syndrome after surgery | 20 | Not named, 3,000 mg | 9 weeks |
| Suzuki 2019Other | Adults with moderate depression | – | Not named | – |
| Condorelli 2019RCT, active or other control | Men with type 1 diabetes and asthenozoospermia | – | Not named, 1,500 mg | 17 weeks |
| Hershman 2018RCT, placebo | Women with breast cancer having taxane chemotherapy | 409 | Not named, 3,000 mg | 24 weeks |
| Parvanova 2018RCT, placebo | Hypertensive type 2 diabetes patients on statin | 229 | Not named, 2,000 mg | 26 weeks |
| Yang 2018RCT, placebo | Dementia with cerebrovascular disease | 56 | Not named, 1,500 mg | 28 weeks |
| Cruccu 2017Single-arm or open-label | Adults with mild to moderate carpal tunnel syndrome | 82 | Not named, 1,000 mg | 17 weeks |
| Jeong 2017Single-arm or open-label | Patients with early Alzheimer's disease | 18 | Not named, 1,500 mg | 73 weeks |
| Suzuki 2017Other | Elderly patient with valproate hyperammonemia | 1 | Not named | – |
| Sun 2016RCT, placebo | Chinese patients with chemotherapy neuropathy | 239 | Not named, 3,000 mg | 8 weeks |
| Li 2016RCT, active or other control | Patients with diabetic peripheral neuropathy | 232 | Not named, 1,500 mg | 24 weeks |
| Bruno 2016Single-arm or open-label | Schizophrenia patients partly responding to clozapine | 15 | Not named, 1,000 mg | 12 weeks |
| Hagen 2015Crossover, placebo | Adults with episodic migraine | 72 | Not named, 3,000 mg | 12 weeks |
| Leombruni 2015RCT, active or other control | Women with fibromyalgia | 65 | Not named, 1,500 mg | 12 weeks |
| Gopal 2015Single-arm or open-label | One woman with tinnitus | 1 | Not named, 1,000 mg | 4 weeks |
| Gavrilova 2015RCT, active or other control | Elderly adults with mild or moderate depression | – | Not named | 8 weeks |
| Baek 2015Pharmacokinetic | Healthy Korean male volunteers | – | Not named, 590 mg | – |
| Malaguarnera 2014RCT, placebo | Office workers with chronic hepatitis C | 62 | Not named, 4,000 mg | 52 weeks |
| Callander 2014Non-randomised controlled | Relapsed or refractory multiple myeloma patients | 32 | Not named | – |
| Hershman 2013RCT, placebo | Women having taxane chemotherapy for breast cancer | 409 | Not named, 3,000 mg | 24 weeks |
| Campone 2013RCT, placebo | Ovarian or prostate cancer patients on sagopilone | 150 | Not named | 18 weeks |
| Beghi 2013RCT, placebo | Adults with early ALS taking riluzole | 82 | Not named, 3,000 mg | 48 weeks |
| Bersani 2013RCT, active or other control | Elderly adults with dysthymic disorder | 80 | Not named | 7 weeks |
| Ledinek 2013RCT, placebo | Multiple sclerosis patients with fatigue | 60 | Not named, 2,000 mg | 4 weeks |
| Malaguarnera 2011RCT, placebo | Patients with overt hepatic encephalopathy | 121 | Not named, 4,000 mg | 13 weeks |
| Malaguarnera 2011RCT, placebo | Patients with minimal hepatic encephalopathy | 67 | Not named, 4,000 mg | 13 weeks |
| Martinotti 2011RCT, placebo | Detoxified alcohol-dependent adults with anhedonia | 64 | Not named, 3,000 mg | 13 weeks |
| Malaguarnera 2011RCT, placebo | Patients with severe hepatic encephalopathy | 61 | Not named, 4,000 mg | 13 weeks |
| Malaguarnera 2011RCT, active or other control | Adults with chronic hepatitis C on interferon | 60 | Not named | 52 weeks |
| Abbasi 2011RCT, placebo | Children aged 7-13 with ADHD on methylphenidate | 40 | Not named, 1,500 mg | 6 weeks |
| Genazzani 2011Single-arm or open-label | Women with stress-induced hypothalamic amenorrhea | 24 | Not named, 1,000 mg | 16 weeks |
| Gavrilova 2011RCT, placebo | Adults with mild Alzheimer's or vascular dementia | – | Not named, 3,000 mg | 12 weeks |
| Martinotti 2010RCT, placebo | Detoxified anhedonic alcohol-dependent adults | 64 | Not named, 3,000 mg | 13 weeks |
| Milazzo 2010RCT, active or other control | HIV patients with lipoatrophy on antiretrovirals | 61 | Not named | 48 weeks |
| Malaguarnera 2009RCT, active or other control | Cirrhosis patients in hepatic coma | 48 | Not named | – |
| Ruggenenti 2009Single-arm or open-label | Non-diabetic adults at increased cardiovascular risk | 32 | Not named, 2,000 mg | 24 weeks |
| Janiri 2009RCT, placebo | Adults dependent on methadone | 30 | Not named, 2,000 mg | 3 weeks |
| Bloomer 2009RCT, placebo | Adults with pre-diabetes | 29 | Acetyl L-carnitine arginate (ALCA), 3,000 mg | 8 weeks |
| Valcour 2009Single-arm or open-label | HIV patients with antiretroviral neuropathy | 21 | Not named, 3,000 mg | 24 weeks |
| Benedini 2009Single-arm or open-label | HIV patients with lipodystrophy | 9 | Not named, 2,000 mg | 35 weeks |
| Malaguarnera 2008RCT, placebo | Cirrhosis patients with minimal hepatic encephalopathy | 125 | Not named | 13 weeks |
| Malaguarnera 2008RCT, active or other control | Elderly adults with chronic fatigue | 96 | Not named | – |
| Memeo 2008RCT, active or other control | Adults with sciatica from herniated disc | 64 | Not named, 1,180 mg | 9 weeks |
| Torrioli 2008RCT, placebo | Boys with fragile X syndrome and ADHD | 63 | Not named | 52 weeks |
| Herzmann 2008Pharmacokinetic | HIV patients with antiretroviral neuropathy, plus healthy controls | 23 | Not named, 3,000 mg | – |
| Arnold 2007RCT, placebo | Children aged 5-12 with ADHD | 112 | Not named, 3,000 mg | 16 weeks |
| Rossini 2007RCT, placebo | Adults with fibromyalgia | 102 | Not named, 1,500 mg | 10 weeks |
| Youle 2007RCT, placebo | HIV patients with antiretroviral neuropathy | 90 | Not named, 2,000 mg | 8 weeks |
| Del Santo 2007Non-randomised controlled | Human subjects, not described | – | Not named | – |
| Türker 2007Other | Healthy volunteers | – | Not named | – |
| Zanardi 2006RCT, active or other control | Adults with dysthymia | 204 | Not named, 1,000 mg | 12 weeks |
| Pueschel 2006RCT, placebo | Adults with Down syndrome | 40 | Not named | 26 weeks |
| Siciliano 2006Non-randomised controlled | Cirrhotic patients with hepatic encephalopathy | 24 | Not named, 500 mg | – |
| Malaguarnera 2006RCT, placebo | Cirrhosis patients with hepatic coma | 24 | Not named | – |
| Osio 2006Single-arm or open-label | HIV patients with painful antiretroviral neuropathy | 20 | Not named, 2,000 mg | 4 weeks |
| Sima 2005RCT, placebo | Adults with chronic diabetic neuropathy | 1,257 | Not named, 1,000 mg | 52 weeks |
| Balercia 2005RCT, placebo | Infertile men with idiopathic asthenozoospermia | 60 | Not named, 3,000 mg | 26 weeks |
| Maestri 2005Single-arm or open-label | Patients with chemotherapy-induced neuropathy | 27 | Not named, 1,000 mg | 2 weeks |
| Bianchi 2005Single-arm or open-label | Patients with chemotherapy-induced neuropathy | 25 | Not named, 3,000 mg | 8 weeks |
| Guideri 2005RCT, active or other control | Girls with Rett syndrome | 22 | Not named | – |
| Herzmann 2005Single-arm or open-label | HIV patients with antiretroviral neuropathy | 21 | Not named | 224 weeks |
| Vermeulen 2004RCT, active or other control | Adults with chronic fatigue syndrome | 90 | Not named, 2,000 mg | 24 weeks |
| Tomassini 2004RCT, active or other control | Multiple sclerosis patients with fatigue | 36 | Not named, 2,000 mg | 12 weeks |
| Hart 2004Single-arm or open-label | HIV patients with antiretroviral neuropathy | 21 | Not named, 3,000 mg | 143 weeks |
| Kwon 2004Pharmacokinetic | Healthy volunteers | 8 | Not named, 500 mg | – |
| Bianchetti 2003Single-arm or open-label | Mild Alzheimer's patients unresponsive to AChE inhibitors | 23 | Not named, 2,000 mg | 13 weeks |
| Mattei 2003Other | Healthy volunteers, motoneurone study | – | Not named | – |
| Calabrese 2003Non-randomised controlled | Patients with active multiple sclerosis | – | Not named | 26 weeks |
| De Grandis 2002RCT, placebo | Adults with diabetic neuropathy | 333 | Not named, 2,000 mg | 52 weeks |
| Pettegrew 2002Single-arm or open-label | Elderly men with mild depression | 2 | Not named | 12 weeks |
| Biagiotti 2001RCT, active or other control | Men with Peyronie's disease | 48 | Not named, 2,000 mg | 12 weeks |
| Thal 2000RCT, placebo | Early-onset Alzheimer's patients aged 45-65 | 229 | Not named, 3,000 mg | 52 weeks |
| Sorbi 2000Crossover, placebo | Patients with degenerative cerebellar ataxia | 24 | Not named | 26 weeks |
| Turpeinen 2000RCT, placebo | Adults with diabetes | 19 | Not named | 52 weeks |
| Giancaterini 2000Crossover, placebo | Type 2 diabetes patients | 18 | Not named | – |
| Di Marzio 1999Single-arm or open-label | Asymptomatic HIV-1 infected adults | 11 | Not named, 3,000 mg | 22 weeks |
| Torrioli 1999RCT, placebo | Fragile X syndrome patients with hyperactivity | – | Not named | – |
| Famularo 1999Single-arm or open-label | HIV patients with AIDS dementia complex | – | Not named | – |
| Grandis 1998Single-arm or open-label | Adults with peripheral neuropathies | 1,097 | Not named, 2,000 mg | 4 weeks |
| Brooks 1998RCT, placebo | Alzheimer's patients, reanalysis of earlier trial | 334 | Not named | 52 weeks |
| Mazzocchio 1997Single-arm or open-label | Healthy controls and spastic patients | 31 | Not named | – |
| Scarpini 1997Single-arm or open-label | HIV patients with painful neuropathy | 16 | Not named, 750 mg | 3 weeks |
| Aymard 1997Single-arm or open-label | Healthy volunteers, not described | – | Not named | – |
| Capecchi 1997Other | Patients with peripheral arterial disease | – | Not named | – |
| Thal 1996RCT, placebo | Mild to moderate Alzheimer's patients | 431 | Not named, 3,000 mg | 52 weeks |
| De Grandis 1995RCT, placebo | Adults with peripheral neuropathies | 426 | Not named, 2,000 mg | 4 weeks |
| Onofrj 1995RCT, placebo | Adults with painful peripheral neuropathies | 94 | ST200, 1,000 mg | 2 weeks |
| Pettegrew 1995RCT, placebo | Alzheimer's patients and healthy controls | 12 | Not named | 52 weeks |
| Rossi 1995Single-arm or open-label | Human volunteers, not described | – | Not named, 2,000 mg | – |
| Quatraro 1995RCT, placebo | Patients with symptomatic diabetic neuropathy | – | Not named | – |
| Bruno 1995Single-arm or open-label | Patients with Alzheimer's disease | – | Not named | – |
| Salvioli 1994Single-arm or open-label | Elderly adults with mild mental decline | 481 | Not named, 1,500 mg | 13 weeks |
| Sabbá 1994RCT, active or other control | Men with peripheral arterial disease and matched controls | 22 | Not named | – |
| Adembri 1994Non-randomised controlled | Patients having aortic reconstructive surgery | 5 | Not named | – |
| Van Hove 1994Single-arm or open-label | Two patients with inborn errors of metabolism | 2 | Not named | – |
| Rossi 1994Single-arm or open-label | Human volunteers, not described | – | Not named | – |
| De Falco 1994Non-randomised controlled | Down syndrome and mentally deficient subjects | – | Not named | 13 weeks |
| Parnetti 1993RCT, active or other control | Mild to moderate Alzheimer's patients | 126 | ST200 | – |
| Katz 1993Single-arm or open-label | Healthy volunteers | 25 | Not named | – |
| Jirillo 1993Non-randomised controlled | Adults with active pulmonary tuberculosis | 20 | Not named | 4 weeks |
| Portela 1993Other | Clinically healthy subjects | – | Not named | – |
| Corbucci 1992RCT, placebo | Patients on bypass with extracorporeal circulation | 100 | Not named | – |
| Mezzina 1992RCT, placebo | Patients with idiopathic facial paralysis | 43 | Not named, 3,000 mg | 4 weeks |
| Sano 1992RCT, placebo | Mild to moderate Alzheimer's patients | 30 | Not named, 2,500 mg | 26 weeks |
| Moncada 1992Single-arm or open-label | Men with idiopathic oligoasthenospermia | 20 | Not named, 4,000 mg | 9 weeks |
| Lino 1992Non-randomised controlled | Healthy young adults | 17 | Not named, 1,500 mg | 4 weeks |
| Parnetti 1992Pharmacokinetic | Alzheimer's type dementia patients | 11 | Not named, 1,500 mg | 9 weeks |
| Corbucci 1992RCT, placebo | Patients with acute cerebral vasculopathy | – | Not named | – |
| Calvani 1992Other | Alzheimer's disease patients | – | Not named | – |
| Spagnoli 1991RCT, placebo | Alzheimer's disease patients | 130 | Not named | 52 weeks |
| Gasparetto 1991Other | Patients with circulatory shock | 115 | Not named | – |
| Genazzani 1991Single-arm or open-label | Women with hypothalamic amenorrhea | 20 | Not named, 2,000 mg | 26 weeks |
| Jirillo 1991RCT, placebo | Adults with active pulmonary tuberculosis | 20 | Not named, 2,000 mg | 4 weeks |
| Postiglione 1991Non-randomised controlled | Chronic stroke patients | 20 | Not named, 1,500 mg | – |
| Falsini 1991Non-randomised controlled | Healthy young volunteers | 18 | Not named | – |
| Rossi 1991Single-arm or open-label | Healthy volunteers | 10 | Not named | – |
| Schieppati 1991Single-arm or open-label | Human volunteers, not described | – | Not named | – |
| Adembri 1991Other | Humans in an ischaemia-reperfusion model | – | Not named | – |
| Cipolli 1990Single-arm or open-label | Elderly adults with mild mental impairment | 469 | Not named, 1,500 mg | 13 weeks |
| Bella 1990RCT, placebo | Older adults with dysthymic disorders | 60 | Not named, 3,000 mg | 9 weeks |
| Passeri 1990RCT, placebo | Elderly adults with mild mental impairment | 60 | Not named, 2,000 mg | 13 weeks |
| Tempesta 1990RCT, placebo | Abstinent alcoholics with cognitive deficits | 55 | Not named, 2,000 mg | 13 weeks |
| Campi 1990RCT, active or other control | Elderly patients with Alzheimer-type dementia | 40 | Not named, 1,000 mg | 13 weeks |
| Rai 1990RCT, placebo | Alzheimer's type dementia patients | 36 | Not named, 2,000 mg | 24 weeks |
| Garzya 1990RCT, placebo | Older adults with depression, aged 70-80 | 28 | Not named, 1,500 mg | – |
| Kelly 1990Pharmacokinetic | Adults with varying degrees of renal impairment | 24 | Not named, 3,000 mg | – |
| Sinforiani 1990Non-randomised controlled | Patients with mild to moderate dementia | 24 | Not named | 12 weeks |
| Puca 1990Single-arm or open-label | Patients with Parkinson's disease | 20 | Not named, 2,000 mg | 1 weeks |
| Arrigo 1990Crossover, placebo | Elderly rehabilitation patients with cerebral circulatory insufficiency | 12 | Not named | – |
| Rosadini 1990Single-arm or open-label | Male patients with brain ischaemia | 10 | Not named, 1,500 mg | – |
| Mazzocchio 1990Single-arm or open-label | Patients with spastic paraparesis | 10 | Not named | – |
| Postiglione 1990Single-arm or open-label | Patients with chronic cerebrovascular disease | 10 | Not named, 1,500 mg | – |
| Genazzani 1990Other | Elderly adults with mild to moderate mental deterioration | – | Not named | – |
| Goety 1990Crossover, placebo | Huntington's disease patients | – | Not named | – |
| Herrmann 1990RCT, placebo | Elderly outpatients with mild to moderate cognitive decline | – | Not named | 12 weeks |
| Battistin 1989Single-arm or open-label | Patients with Alzheimer's or mixed dementia | 30 | Not named, 2,000 mg | – |
| Schieppati 1989Single-arm or open-label | Normal subjects and spastic patients | 13 | Not named, 2,000 mg | – |
| Mazzocchio 1989Single-arm or open-label | Healthy volunteers | 6 | Not named | – |
| Marzo 1989Pharmacokinetic | Healthy volunteers | 6 | Not named, 500 mg | – |
| Gambi 1989Single-arm or open-label | Healthy volunteers and dementia patients | – | Not named | – |
| Passeri 1988RCT, placebo | Elderly adults with mild mental impairment | 30 | Not named, 2,000 mg | 13 weeks |
| Guarnaschelli 1988Single-arm or open-label | Patients with involutional brain ageing | 20 | Not named, 1,500 mg | 26 weeks |
| Sannita 1988Crossover, placebo | Healthy young volunteers | 10 | Not named | – |
| Martignoni 1988Other | Humans, not stated | – | Not named | – |
| Tempesta 1987Crossover, placebo | Hospitalised elderly with depression | 24 | Not named | 4 weeks |
| Bonavita 1986Non-randomised controlled | Elderly adults with senile brain decline | 40 | Not named, 3,000 mg | 6 weeks |
| Gasparetto 1986Other | Patients with circulatory shock | – | Not named | – |
| Nanni 1985Non-randomised controlled | Surgical patients, septic or non-septic | 67 | Not named | – |
| Rossini 1985Single-arm or open-label | Healthy volunteers and patients with brain lesions | 25 | Not named | – |
| Acierno 1983Other | Alzheimer's disease patients | – | Not named | – |
| Testa 1982Other | Patients with mental deterioration | – | Not named | – |
| Giordano 1981Other | Acute myocardial infarction patients | – | Not named | – |
Safety
What's known about safety
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In trials
No serious side effects were linked to it in a review of 4 placebo-controlled trials, and side effects overall were about as common as on placebo. Headache and stomach upset were among those reported. Trials ran for up to a year at 1,500 to 3,000 mg a day.
Li 2015, review of 4 trials; Rolim 2019, Cochrane review of 4 trials at 1,500 to 3,000 mg a day
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In the UK
Acetyl-L-carnitine isn't treated as a novel food, so it can be sold in food supplements. We found no official UK or EU upper limit.
EU Novel Food Status Catalogue (not novel in food); FSA novel foods guidance; searches of EFSA and FSA, Oct 2026
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Check first
In a large trial in women having taxane chemotherapy, nerve symptoms were worse with it than with placebo. A case report describes mania returning in a man with bipolar disorder, and it hasn't been studied in pregnancy. Speak to a doctor first if any of these applies to you.
Hershman 2013, 409 women at 3,000 mg a day; Goodison 2017, case report; no pregnancy trials found, Oct 2026
How we built this
Where these studies come from
We list every published study of acetyl-L-carnitine in people. This first version is built from each study's summary; full-paper checks come next.
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We search
PubMed, the world's main library of medical research, for every paper on L-theanine.
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We keep studies in people
Lab and animal work is counted but left out of the list, because it doesn't tell you what happens in people.
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We note the basics
Who took part, how many, how much and for how long, from each study's published summary. A second check corrects what the first read gets wrong.
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We read them in full
Results appear once we've read the whole paper and checked every number. The date at the top shows when this entry was last updated.
Download the study list
Every study in people as a spreadsheet, 160 rows, free to reuse with a link back.
Versions
Each update to the data gets a new version number, so you can tell what changed and when.
See every version
1.0 · 19 Oct 2026. First release. Every published study giving acetyl-L-carnitine on its own to people is listed from its summary. None is read in full yet.
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