||Self-rated health (SRH) is a widely used health indicator predicting morbidity and mortality in a wide range of populations. However, little is known about the stability and biological basis of SRH. The aim of this study was to map the stability of SRH from adolescence to early adulthood, and to examine the relationships between SRH and biological dysregulation, in terms of allostatic load (AL). The AL score comprises the eleven biomarkers systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), cholesterol, high-density lipoprotein cholesterol (HDL), triglycerides, waist-hip ratio (WHR), diabetes risk profile, glucose, C-reactive protein (CRP) and body mass index (BMI). Eleven years prospective data from the Nord-Trondelag Health Study (HUNT), Norway, were utilised. Baseline data were gathered from 9141 adolescents (mean age 15.9 years) in the Young-HUNT I survey (1995-1997) and follow-up data were gathered from the adult HUNT3 survey (2006-2008). Altogether, 1906 respondents completed both questionnaires and clinical measurements in both studies. Cross-tables for SRH at baseline and follow-up showed that SRH remained unchanged in 57% of the respondents. Only 3% of the respondents changed their ratings by two steps or more on a four-level scale. Further, linear regression analyses adjusted for age and gender revealed that SRH in adolescence predicted AL in young adulthood. Similar patterns were found for most of the individual biomarkers. The consistency found in SRH from adolescence to young adulthood, and its association with AL across time, indicate that routines for dealing with SRH early in life may be a central strategy to prevent morbidity in the adult population.