Amyotrophic lateral sclerosis (ALS) is a serious rapidly progressive disease of the nervous system. The mean survival from the time of diagnosis is 2.5 years. Apart from Riluzole, there is no effective treatment. Care of advanced ALS will have a cost of 4-8 million NOK (Norwegian kroner) per year. Research i.a. from the investigators department has shown that increased activity in histone deacetylation enzymes (sirtuins) together with increased access to Nicotinamide Adenine Dinucleotide (NAD) can delay disease progression. Nicotinamide riboside (NR) can increase cells' access to NAD and Pterostilbene will stimulate sirtuins. The investigators want to study whether combination therapy with NR and Pterostilbene can inhibit neurodegeneration in ALS and thereby delay disease development, increase survival and improve quality of life in ALS. In the NO-ALS extension study the investigators will follow the patients who completed the original NO-ALS study. Objectives are to evaluate adverse events and give patients possibility of compassionate use, and secondarily to see if the combination of NR and pterostilbene (EH301) will decrease progression of motor symptoms and loss of vital capacity, and increase survival time in patients with ALS.