What Happens When You Breathe Pine Air

The Research Behind Forest Bathing and Immune Function

For centuries, healers in Japan and across East Asia prescribed time in the forest as medicine. In the 1980s, the Japanese government gave this practice a name: Shinrin-yoku, meaning "forest bathing." What began as a wellness tradition has since become one of the more thoroughly documented areas of environmental health research.

The key question researchers wanted to answer was not whether people felt better after walking among trees. That was obvious. The question was: why? What is the biological mechanism that explains improved mood, reduced cortisol, and measurably better immune markers after time spent in nature?

Alpha-Pinene and Beta-Pinene: The Active Molecules

Pine trees continuously release volatile organic compounds called phytoncides into the surrounding air. The two most studied are alpha-pinene and beta-pinene -- bicyclic monoterpene molecules with a distinctive crisp, resinous aroma. When you step into a pine forest and breathe, these terpenes enter your respiratory tract and absorb through the mucosal lining of your airways.

Researchers believe these compounds interact with the autonomic nervous system, shifting the body toward a parasympathetic (rest-and-repair) state. Heart rate drops. Cortisol decreases. And critically, immune activity rises.

Natural Killer Cells and the 50% Finding

Dr. Qing Li of Nippon Medical School in Tokyo has spent decades measuring exactly what forest bathing does to human blood. In a landmark series of studies, Dr. Li and his colleagues sent participants on two-hour forest walks over multiple days and then measured their Natural Killer (NK) cell activity -- a key front-line component of innate immunity that targets abnormal cells.

The results were striking: participants who spent time in pine-dominant forests showed NK cell activity increases of 50% or more compared to urban control walks of identical duration. These effects were not fleeting. Follow-up measurements showed elevated NK activity persisting for up to 30 days after the initial forest exposure. Participants also showed increases in anti-cancer proteins including perforin, granzyme A, and granulysin.

Critically, when researchers conducted hotel-room studies where participants were simply exposed to diffused phytoncide-rich air (without any exercise or natural scenery), the immune effects were still observed -- suggesting the terpenes themselves, not the walking, are driving a meaningful portion of the response.

How Forest MONQ Connects to This Science

Forest MONQ was formulated with this science in mind. The blend brings together Pine (the primary phytoncide source), Sandalwood (a grounding sesquiterpene-rich wood with its own aromatic complexity), and Frankincense (traditionally used in meditative and immune-supporting contexts for thousands of years). Together, these three ingredients recreate the aromatic character of a walk through a coniferous forest.

MONQ uses a retronasal olfaction delivery method: you draw the aromatic mist gently into your mouth, then exhale through your nose. This route -- mouth in, nose out -- engages the olfactory epithelium from the back of the nasal cavity, maximizing the aromatic signal to the brain's limbic system while keeping the mist out of the lungs. It is the same pathway that activates when you bite into food and experience its full aromatic complexity.

Users report that Forest MONQ creates a moment of calm forest immersion without requiring proximity to an actual pine tree. Whether at a desk, in transit, or winding down at home, it brings the signature scent of Shinrin-yoku into any environment.

Watch: Pine Terpenes and Your Immune System

See the science in action. Our latest video breaks down how forest air affects NK cell activity.