The present disclosure provides methods for manufacturing or producing glatiramer acetate having a Mp of 5000-9000 Da. These methods include: polymerizing N-carboxy anhydrides of L-alanine, benzyl-protected L-glutamic acid, trifluoroacetic acid (TFA)-protected L-lysine, and L-tyrosine to generate a sample comprising intermediate-1 treating the sample comprising intermediate-1 to partially depolymerize the protected copolymer and deprotect benzyl-protected L-glutamic acid, measuring the viscosity of the sample comprising intermediate-1 during the treatment, and ending the treatment when the viscosity of the sample is within an endpoint range, thereby generating a sample comprising intermediate-2 treating the sample comprising intermediate-2 to deprotect TFA-protected L-lysine, thereby generating intermediate-3 further processing the intermediate-3 to generate a sample glatiramer acetate and purifying the glatiramer acetate to generate a composition comprising purified glatiramer acetate having a Mp of 5000-9000 Da.
