diff --git a/src/pyEQL/solute.py b/src/pyEQL/solute.py
index 64bad4b1..ed01abfd 100644
--- a/src/pyEQL/solute.py
+++ b/src/pyEQL/solute.py
@@ -105,14 +105,15 @@ def from_formula(cls, formula: str):
         of the IonDoc.
         """
         pmg_ion = Ion.from_formula(formula)
-        f = pmg_ion.reduced_formula
+        rform = pmg_ion.reduced_formula
+        f, factor = pmg_ion.get_reduced_formula_and_factor()
         charge = int(pmg_ion.charge)
         els = [str(el) for el in pmg_ion.elements]
-        mw = f"{float(pmg_ion.weight)} g/mol"  # weight is a FloatWithUnit
+        mw = f"{float(pmg_ion.weight / factor)} g/mol"  # weight is a FloatWithUnit
         chemsys = pmg_ion.chemical_system
 
         return cls(
-            f,
+            rform,
             charge=charge,
             molecular_weight=mw,
             elements=els,
diff --git a/tests/test_solute.py b/tests/test_solute.py
index 003a70fd..7b017ed1 100644
--- a/tests/test_solute.py
+++ b/tests/test_solute.py
@@ -17,3 +17,6 @@ def test_from_formula():
     assert s.n_elements == 1
     assert s.oxi_state_guesses == ({"Mg": 2.0},)
     assert s.molecular_weight == "24.305 g/mol"
+    s2 = Solute.from_formula("O6")
+    assert s2.formula == "O3(aq)"
+    assert s2.molecular_weight == "47.9982 g/mol"