Arrowhead vs Kirkland Signature: which water is healthier?
Updated · Scores from third-party lab reports · How we score
Kirkland Signature is the healthier choice, scoring 63/100 versus 57/100 for Arrowhead. The biggest differences are contaminants and PFAS testing.
Arrowhead
Arrowhead Mountain Spring Water Gallon
57
Kirkland Signature
Kirkland Signature Purified Water Plastic Bottle
63Side-by-side comparison
| Arrowhead | Kirkland Signature | |
|---|---|---|
| Purity score | 57/100 | 63/100 |
| Product compared | Arrowhead Mountain Spring Water Gallon | Kirkland Signature Purified Water Plastic Bottle |
| Type | Still | Still |
| Water source | Mountain Spring | Municipal Supply |
| Packaging | Plastic | Plastic |
| Microplastics risk | High | High |
| Lab tested | Yes | Yes |
| PFAS tested | No | Yes |
| Contaminants flagged | 6 | 1 |
| pH | 7.5 | 5.9 |
| TDS (minerals) | 135.5 ppm | — |
| Fluoride | 0.5 mg/L | 0 mg/L |
Score breakdown
| Factor | Arrowhead | Kirkland Signature |
|---|---|---|
| Lab report indexed | 45/45 | 45/45 |
| Contaminants | 1/50 | 17/50 |
| Water source | 25/25 | 15/25 |
| Mineral preservation | 17/17 | 17/17 |
| Packaging material | 2/22 | 2/22 |
| Cap material | 7/7 | 7/7 |
| PFAS testing | 0/5 | 5/5 |
Each brand is represented by its most popular product. See all products from Arrowhead and Kirkland Signature.
Frequently asked questions
Which is better, Arrowhead or Kirkland Signature?
Kirkland Signature is the healthier choice, scoring 63/100 versus 57/100 for Arrowhead. The biggest differences are contaminants and PFAS testing.
Is Arrowhead or Kirkland Signature better for avoiding microplastics?
Arrowhead (plastic) has a high microplastics risk and Kirkland Signature (plastic) has a high risk, based on packaging material.
Which has more minerals, Arrowhead or Kirkland Signature?
Total dissolved solids (TDS) is not reported for both products, so check each product page for its mineral list.