The present invention provides improved formulations of botulinum toxin that increase delivery of the botulinum toxin to neural and associated tissues and exhibit a higher specific neurotoxicity and higher potency (in LD50 Units) than available formulations of botulinum toxins. These improved formulations enable physicians to treat a wide variety of pathological conditions with a lower toxin load that reduces the risk of inducing an immune response against the toxin and its associated proteins that may ultimately lead to the development of toxin resistance. These benefits are particularly important in the treatment of conditions that require high-dose or chronic administration of botulinum toxin. Additionally, the decreased in LD50 Unit doses of inventive formulations allows for controlled administration limits diffusion. The present invention also provides methods of treating neuromuscular diseases and pain, using low-dose botulinum toxin.