There appear to be two main challenges to the thymus gland's effective functioning: emotional stress and lack of fulfillment may result in fewer and less active white blood cells; and aging – it gradually begins to atrophy and get replaced by fat and connective tissue, starting in our twenties.

The thymus gland, which is located in the upper chest (above the heart, between the lungs, and slightly below the thyroid), has a major role in our immune system. It produces a certain type of white blood cells called T-lymphocytes or T-cells.

Unlike antibodies (immunoglobulins) which are created already being geared to targeting a particular type of virus or bacteria via the specific antigen or protein attached to them, T-cells need to be 'instructed' on what to do by the Thalamus.

This process of programming the T-cells to recognize and destroy pathogens (either by themselves, or by controlling some of the white cells which maintain certain antibodies which do it) is known as "cell-mediated immunity," and it's how we resist infections from mold-like bacteria like allergens, fungi, parasites, yeast, and some viruses. And when it goes awry, we either become susceptible to certain diseases if it underperforms, or we get subjected to an autoimmune disease if it overperforms and attacks our own cells as if they are enemy invaders.
Ingredients:

Each veg. capsule contains:

200 mg Thymus (source: ovine)
25 mg B-6 (pyridoxal-5-phosphate 37.3 mg)
25 mg Zinc picolinate

USP pharmaceutical grade. Whole desiccated raw tissue concentrates from pasture-fed New Zealand lamb, free of growth hormones, antibiotics, or chemical additives.

Life Choice Thymus Gland contains no wheat, corn, yeast, soy or dairy. The capsules are made from a vegetarian source: no gelatin used. Non-GMO.
Suggested Usage:

Adults: Take 1 capsule daily with food, or as directed by a healthcare practitioner. Take a few hours before or after taking other medications. Consult a healthcare practitioner for use beyond 3 months.
Warnings:

Do not use a thymus gland supplement if you are pregnant or breastfeeding, or if you have an immune system disorder, or if you are taking immunosuppressant medication.