Linezolid works in 2 to 3 days in most cases, but patients with severe infections or relatively poor drug sensitivity may take longer to work; some patients may see rapid results in about 1 day. Linezolid is an antibiotic that is used to treat infections caused by drug-resistant gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus. For the above infectious diseases, the effect of the treatment will usually be seen in 2~3 days, and repeat blood tests, C-reactive protein and other inflammatory indicators are needed to assess the efficacy of the treatment. However, the time for linezolid to take effect is not fixed, for patients with severe infections or those whose sensitivity to linezolid is not too good, sometimes 2~3 days is not enough to see obvious results, and you need to wait longer, or even 1 week or so for the condition to improve significantly. There are also some patients with mild infections or very good sensitivity to linezolid, the effect of treatment may be faster, or even about 1 day to see the effect of the next day after the use of the drug will be effective control of the body temperature, or a significant drop.