Wow. I'm sorry guys I am unfortunately an arm-chair expert on Hypothyroidism having gone through a couple of years of hell with it & I disagree with the previously offered advice.
Actual Hypothyroidism cannot be treated effectively with anything other than thyroid hormone supplementation. Regarding your friend's test results:
Free T3 1.68 (normal ranges 2.1-5.34)pg/ml She's got no T3. None. She must feel like absolute garbage. I'm amazed she's functioning. When my T3 is that low (below range) I'm practically crawling on the floor. There is a CHANCE that She will do ok on Synthroid (synthetic T4) supplementation but if I were her I'd want T4 AND T3.
I'd want a doc that would dose me with cytomel (synthetic T3) starting at 5mcg a.m. & 5mcg p.m. and retest my FREET3 levels every six weeks and increase my dose after re-test until my FREET3 level was at the top 2/3 to 3/4 of range. It typically takes six months to one year of this process (test, increase dose, test, increase dose etc.) to get the levels OPTIMIZED.
Free T4 1.03 (normal ranges 0.8-2.01) Again she's got not too much T4. The purpose of T4 is for our body to convert it into the active thyroid hormone T3. The problem is that most women who have hypO DO NOT CONVERT so dosing with Synthroid only is ineffective. You can get the FREET4 levels as high as you want but if the FREET3 levels aren't right the patient will experience no improvement in symptoms.
TSH 0.90 (normal ranges 0.5-4.7) Now this is an odd reading. Her TSH is quite low. TYPICALLY when someone is hypothyroid TSH is HIGH. TSH is Thyroid Stimulating Hormone produced by the pituitary gland to urge the thyroid to make T4 and convert it to T3. TSH isn't actually a thyroid test at all its a pituitary test.
HOWEVER with TSH low and Low T3 and Low T4 I begin to suspect Hashimotos which is an autoimune thyroid disease. Have your friend get tested for Hashimotos antibodies (Antithyroid peroxidase antibody & Antithyroglobulin antibodyAntithyroglobulin antibody) maybe she was tested already does her lab slip say TPA or TPO antibodies on it anywhere?
BEYOND THAT your friend needs to find a doctor that knows how to treat her. Its good that they ran the FREET3 test but suggesting natural supplementation is absolutely ludicrous. Send your friend to stopthethyroidmadness.com for a beginner course on what she's dealing with.
Gluten Free diet might be legit many Hypothyroid people are gluten intollerant but not all (I'm not).
She is going to need to get over not wanting to be on synthroid the rest of her life. You can't fix a broken thyroid and she WILL need to supplement her thyroid hormones by taking them orally. She won't feel well/normal/beabletoloseweight until she gets some T3 in her body. SYNTHROID AND CYTOMEL are not "drugs" they are HORMONES.
NO ONE should eat soy but ESPECIALLY NOT anyone with thyroid problems.