This is the third ingredient in Driscoll Protocol’s supplement. Unlike the prior two, the evidence is strongly favorable to it’s use — symptoms will reduce BUT if you stop, they will return.
Below is a summary of the major findings on PubMed
- “The pool of different carnitine derivatives is formed by acetyl-L-carnitine (ALC), propionyl-L-carnitine (PLC), and isovaleryl-carnitine. ALC may have a preferential effect on the brain tissue…. it may be of benefit in treating Alzheimer’s dementia, depression in the elderly, HIV infection, chronic fatigue syndrome, peripheral neuropathies, ischemia and reperfusion of the brain, and cognitive impairment associated with various conditions… There were no significant differences in plasma or urinary total, free or esterified (acyl) carnitine between UK patients with CFS and the control groups or in renal excretion rates of these compounds.” 
- “In patients with chronic hepatitis C and not with IBS, fatigue scores were negatively correlated with plasma levels of carnitine.” 
- “Contradictory reports have suggested that serum free carnitine and acylcarnitine concentrations are decreased in patients with chronic fatigue syndrome (CFS) and that this is a cause of the muscle fatigue observed in these patients. Others have shown normal serum free carnitine and acylcarnitines in similar patients.” 
- “The previously reported decreased level of acylcarnitine in CFS patients was not confirmed. There were also no significant differences in levels of total carnitine, free carnitine and 20 carnitine esters between CFS patients and controls.” 
- A randomised controlled trial comparing duloxetine and acetyl L-carnitine in fibromyalgic patients: preliminary data . “randomised to receive duloxetine 60 mg/day or acetyl L-carnitine 1500 mg/day (500 mg three times a day) … Both drugs had a positive effect on the physical component of the quality of life, but only duloxetine improved the psychological component.”
- Double-blind, multicenter trial comparing acetyl l-carnitine with placebo in the treatment of fibromyalgia patients. “Significantly larger improvements in SF36 questionnaire were observed in LAC than in placebo group for most parameters. Treatment was well-tolerated.”
- ” The level of L-carnitine was 6.4336 +/- 3.4225, significantly lower than that of the control group and the L-carnitine level was increased 2 weeks after supplementary treatment, together with improvement of symptoms.” 
- “Clinical global impression of change after treatment showed considerable improvement in 59% of the patients in the acetylcarnitine group and 63% in the propionylcarnitine group, but less in the acetylcarnitine plus propionylcarnitine group (37%). Acetylcarnitine significantly improved mental fatigue (p =.015) and propionylcarnitine improved general fatigue (p =.004). Attention concentration improved in all groups, whereas pain complaints did not decrease in any group. Two weeks after treatment, worsening of fatigue was experienced by 52%, 50%, and 37% in the acetylcarnitine, propionylcarnitine, and combined group, respectively. In the acetylcarnitine group, but not in the other groups, the changes in plasmacarnitine levels correlated with clinical improvement.” 
- Long-chain acylcarnitine deficiency in patients with chronic fatigue syndrome. Potential involvement of altered carnitine palmitoyltransferase-I activity. 
- Carnitine is unlikely to be low when measured, BUT
- Supplementation of l-carnitine results in improvements with both IBS and CFS
- 500 mg of acetyl L-carnitine taken three times a day showed results.
- This must be ONGOING — if you stop, the benefits will be loss. This is symptom mitigation only