Lorenzo’s Oil is a mix of unsaturated fatty acids that is used by patients with adrenoleukodystrophy (ALD).

Lorenzo’s Oil does not alter the progression of ALD in patients who have neurological involvement, but it may prevent neurological dysfunction when used by patients who do not yet have symptoms.

How Lorenzo’s Oil works

ALD is caused by a mutation in the ABCD1 gene. This gene provides instruction to build a transporter protein that mediates the transport of saturated very long-chain fatty acids (VLCFAs) into peroxisomes. Peroxisomes are small compartments within the cell that are involved in the breakdown of many molecules, among them VLCFAs.

The insufficient transport of VLCFAs into peroxisomes leads to their accumulation in the blood, brain, and spinal cord. Here, they trigger an inflammatory response that leads to the destruction of myelin, a protective sheath that insulates nerve cells in the brain.

VLCFAs are produced within the body by the elongation of shorter saturated fatty acids. The elongase enzymes that perform this elongation also can interact with unsaturated fatty acids, in which case no VLCFAs are produced.

Lorenzo’s Oil is a 4:1 mix of two unsaturated fatty acids, oleic acid, and erucic acid. They inhibit the production of VLCFAs, which reduces their accumulation. The oil is administered at a dose that provides approximately 20 percent of the total calories needed.

Lorenzo’s Oil in clinical trials

An open-label clinical trial included 89 boys with ALD who were neurologically asymptomatic and had a normal brain MRI. They received 2-3 ml Lorenzo’s Oil per kg body weight, per day, and followed a diet that was moderately restricted in fat from other sources (10-15 percent of total calories).

The mean follow-up period was 6.9 years during which VLCFA levels in the blood and the development of MRI and neurological abnormalities were monitored.

Lorenzo’s Oil led to a reduction in VLCFA levels in the blood, and low VLCFA levels correlated with a better clinical outcome, confirming the mechanism of Lorenzo’s Oil and the role of VLCFAs in disease progression.

Of the 89 boys, 24% developed MRI abnormalities, and 11% developed both neurological and MRI abnormalities. Data on the progression of untreated asymptomatic patients are limited, but a retrospective analysis estimated that 35% of untreated ALD patients develop neurological symptoms by age 10.

An open-label study included 45 men with adrenomyeloneuropathy (AMN, an ALD subtype that appears in adulthood) who did not have evidence of inflammatory brain involvement.

Participants were followed for a mean of 6.7 years, and disease progression was assessed by the adult adrenoleukodystrophy clinical scale (AACS). The AACS is a score from 0-24 and includes measures of motor and bladder function, sensory symptoms, and cerebral functions.

The mean progression of AACS was 1.5 units and remained stable in 22 patients. The estimated progression without treatment is 2.6 units, which is based on historical data. Disease progression is, however, highly variable in untreated patients.

The efficacy of Lorenzo’s Oil has never been shown in controlled randomized clinical trials. One larger placebo-controlled trial (NCT00545597) that aimed to assess Lorenzo’s Oil in 240 patients with AMN was discontinued due to adverse reactions in the control group.

Additional information

The use of Lorenzo’s Oil leads to a moderate reduction in platelet counts in 30-40% of patients. Platelets are small blood cells that form blood clots to stop bleeding. This reduction, however, usually is not associated with clinically significant bleeding. When counts fall below 80,000/mm3, Lorenzo’s Oil (after consulting with a physician) should be discontinued and resumed at a lower dose.


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