An estimated 5–10% of adults do not seroconvert after a three-dose primary course of hepatitis B vaccines, and are considered non-responders. Many approaches have been used to induce immunity in healthy adult non-responders, but few studies have compared their relative effectiveness. We conducted a systematic review and meta-analysis of seroconversion rates after additional doses of four approaches: 20 mcg or 40 mcg intramuscular (IM), and 5 mcg or 20 mcg intradermal (ID). The search identified 13 articles encompassing 16 studies (N = 1067) that met the eligibility criteria. Seroconversion rates after additional doses of each approach were pooled and estimated. After one additional dose, the four approaches produced very similar seroconversion rates and we did not find any evidence to support the use of 40 mcg IM in healthy adults.