Perform a Patch Test (Essential for Sensitive Skin)

• Why: The formula contains common potential irritants and allergens like Phenoxyethanol (a preservative), fragrance components (not listed but often included in commercial products), and various esters (Isopropyl Myristate, Ethylhexyl Palmitate), which can cause clogged pores or breakouts for some skin types.
• Precaution: Before applying it to your face, test the product on a small, discreet area like your inner arm or behind your ear. Wait 24 hours to check for any signs of redness, itching, or swelling. 

Be Mindful of Comedogenic Ingredients

• Why: Ingredients like Isopropyl Myristate, Ethylhexyl Palmitate, and Isostearic Acid are known to have a moderate to high comedogenic rating, meaning they can clog pores.
• Precaution: If you have very oily, acne-prone, or reactive skin, this product may not be suitable for daily use. Ensure you double cleanse thoroughly every night to remove all traces of the product. 

Work Quickly and Blend Immediately

• Why: The formula is designed with volatile silicones (Isododecane, Phenyl Trimethicone) that evaporate quickly. This means the product will set and become difficult to blend after a short period.
• Precaution: Apply the product to one section of your face at a time (e.g., one cheekbone) and blend it out immediately. Do not apply it to your entire face first and then try to blend, as it may set patchy and be hard to move. 

Avoid The Waterline & Direct Eye Area

• Why: This is not an eye product. The presence of Butylated Hydroxytoluene (BHT) and various waxes, while safe for skin, are not intended for use directly in the eyes and could cause irritation.
• Precaution: Use caution when contouring the nose or brow bone. Do not use the pen on your eyelids or as an eyeliner. 

Note the Presence of BHT

• Why: Butylated Hydroxytoluene (BHT) is a common synthetic antioxidant used to prevent oils in the formula from going rancid. While approved for use in cosmetics in small quantities, some individuals may prefer to avoid it due to personal sensitivity or preference.
• Precaution: If you have a known sensitivity to BHT, you should avoid this product. 

Store Properly

• Why: The blend of waxes and oils can be sensitive to heat.
• Precaution: Store the pen in a cool, dry place away from direct sunlight. Do not leave it in a hot car, as this could cause the formula to separate or melt, ruining the applicator and consistency.
• And Keep out of reach of children for safety. 

In summary: While this is a high-performance product, its efficacy depends on proper use. The most critical precautions are to patch test if you have sensitive skin, to blend with speed due to its quick-setting nature, and to avoid the eye area. Always ensure your skin is clean before application and thoroughly cleansed after use.