Weight variation is one of the quality control parameters used to ensure the consistency of the amount of drug substance in each dosage unit within a batch. The objectives of this study were to compare weight variation of Andrographis capsules according to 5 pharmacopoeial methods, Thai Herbal Pharmacopoeia (THP), British Pharmacopoeia (BP), European Pharmacopoeia (EP), The International Pharmacopoeia (Ph. Int.) and The United States Pharmacopeia (USP), and to use it as an example supporting a revision to the THP. A total of 52 products were calculated for average weight of Andrographis powder and tested for weight variation as described in 5 pharmacopoeias. The weight of 24 products (46%) did not meet the label within a 10% margin. The differences between testing procedures and acceptance criteria were observed in each standard which may lead to different conclusions. The results showed that 29 products (56%) complied with all standards whereas 13 products (25%) met the THP standard but failed the others. It was apparent that the requirement as per THP is less stringent than those of international standards and may be insufficiently restrictive for quality control of herbal medicines.