The scent seems very sharp and strong when I first open the bottle. Is this normal?

Yes, this is completely normal for a pure, natural essential oil like this lemongrass (Cymbopogon citratus). The oil is highly concentrated, so the aroma directly from the bottle is the full, unadulterated scent profile—a sharp, intensely citrus-herbal character. When used in an aroma lamp or diffuser with air, the scent molecules disperse and the aroma often 'softens', revealing more of its green, grassy notes and creating the lighter, fresher atmosphere described. If you find the initial strength overwhelming, simply start with fewer drops than suggested (e.g., 1-2 drops instead of 3-4). You can also blend it with complementary essential oils that have milder base notes, like a drop of sandalwood or cedarwood, to round out the sharp top notes. The strength is a sign of a pure, undiluted product.