The present invention generally relates to dosage forms for oral administration including one or more gelling agents. In particular, the present invention is directed to gelling agent-based dosage forms that are easily administered and taken, or swallowed. The present invention is also directed to gelling agent-based dosage forms that exhibit relatively low syneresis, are thermally stable, exhibit substantially constant active ingredient concentration, and/or exhibit one or more advantageous rheological properties. In particular, the present invention is directed to such gels containing one or more omega-3 fatty acids. The gelling agent-based dosage forms of the present invention are suitable for administration of a relatively large dose of active ingredient. The gelling agent-based dosage forms of the present invention are also suitable for administration of multiple active ingredients. Dosage forms of the present invention also provide tamper resistance and, thus, prevent recovery or diversion of active ingredients contained therein. The gelling agent-based dosage forms are also suitable for use as gastro-retentive and sustained release dosage forms.