Oxygen is generally not required on this trek as most parts of the trek are below 4,000m (13,123ft.) except the highest section on the Khayer Lake (4,500m/14,764ft.) Our Khopra Ridge Community trek itinerary is designed in such a way so that it allows enough acclimatization. We provide Diamox tablets, a medication that suppresses altitude sickness symptoms, to trekkers right from the beginning of the trek to prevent from falling sick. However, in case a person shows symptoms of altitude sickness and cannot proceed further, we will descend to a lower altitude immediately.