Function Health vs SiPhox Health
SiPhox Health is cheaper to start ($298 vs $365 per year, lowest published plans). Function Health scores higher overall (9.0 vs 7.0).
By Julian Caraulani · prices checked
Quick verdict
Our pick between the two: Function Health
Function Health scores 9.0/10 against 7.0 for SiPhox Health, ahead on price and clinical care. SiPhox Health can still be the better fit: it is best for people who want to test at home on their own schedule and track change over time.
Side by side
| Function Health | SiPhox Health | |
|---|---|---|
| Lowest price | $365/yr (yearly membership, auto-renews) | $298/yr (per testing cycle; slowest cadence is every 6 months) |
| Our score | 9.0/10 | 7.0/10 |
| Treatments | Longevity memberships | At-home test kits, Hormone panels |
| Medication in price | Not stated | Not stated |
| Drugs dispensed | Not stated | Not stated |
| Labs | Not stated | Not stated |
| Membership | Not stated | Not stated |
| Insurance | No; self-pay | No; self-pay |
| States | 48 states (not RI, HI), per its own site (2026-10-31) | 48 states (not HI, NY), per its own site (2026-10-31) |
| Cancellation | Cancel and rejoin anytime; no pauses; no refunds for prior payments; auto-renews annually at then-current price. | Cancel, pause or modify anytime from the account portal; keep access to past data. |
| FDA warning letters | None found (October 31, 2026) | None found (October 31, 2026) |
| Trustpilot | 4.5/5 (3,102 reviews) | 4.7/5 (718 reviews) |
| Best for | People who want the widest yearly panel, retested twice, in one membership. | People who want to test at home on their own schedule and track change over time. |
| Prices checked | 2026-10-31 | 2026-10-31 |
Function Health: a closer look
Yearly membership: 100+ markers at Quest, a mid-year retest and a clinician summary. We searched the FDA warning-letter database on October 31, 2026 and found no letter naming Function Health.
In its favour
- Measures ApoB, Lp(a), fasting insulin, omega-3 and heavy metals in the base price
- Two draws a year included
- Clinicians review every result
To weigh
- No refunds for prior payments, and membership auto-renews at the then-current price.
- '160+ lab tests' counts the mid-year retest; the annual draw is 100+.
- NY/NJ residents can be billed lab fees on top of the membership, amount not disclosed upfront.
- Not available in Rhode Island, Hawaii or Puerto Rico.
SiPhox Health: a closer look
At-home upper-arm kits on a subscription, tested monthly, quarterly or twice a year. We searched the FDA warning-letter database on October 31, 2026 and found no letter naming SiPhox Health.
In its favour
- At-home upper-arm collection, no lab visit
- Cancel, pause or switch panels any time
- States CLIA and CAP accredited partner lab
To weigh
- Headline price excludes $25 shipping per cycle; $99 is first cycle only.
- Not available in New York or Hawaii.
- Privacy policy allows selling aggregated data and sharing de-identified data with AI vendors.
- Wellness-only service; outsourced lab, recurring subscription billed per cycle.
Which should you choose?
Choose Function Health
Best for people who want the widest yearly panel, retested twice, in one membership. Its lowest all-in plan is $365/yr (yearly membership, auto-renews).
Check Function Health's priceChoose SiPhox Health
Best for people who want to test at home on their own schedule and track change over time. Its lowest all-in plan is $298/yr (per testing cycle; slowest cadence is every 6 months).
Check SiPhox Health's priceFunction Health vs SiPhox Health: questions people ask
Is Function Health or SiPhox Health cheaper?
SiPhox Health starts lower at $298 per year versus $365 at Function Health, comparing each program's lowest all-in plan.
Which is better, Function Health or SiPhox Health?
On our published score Function Health rates 9.0 and SiPhox Health rates 7.0. Function Health is best for people who want the widest yearly panel, retested twice, in one membership; SiPhox Health is best for people who want to test at home on their own schedule and track change over time.
Do Function Health and SiPhox Health offer the same treatments?
Function Health: Longevity memberships. SiPhox Health: At-home test kits, Hormone panels.
Does either include the medication in the price?
Function Health: not stated. SiPhox Health: not stated.
Blood Test Watchdog compares testing services. It is not medical advice, does not interpret results and does not publish reference ranges as advice. Talk to a licensed clinician about which tests you need and what your results mean. Partner links may earn us a commission; our score never depends on it. Compare other programs.